0001656423-24-000059 | 10-Q | XBRL Viewer

Derivative Instruments and Hedging Activities

9 Months Ended

Sep. 30, 2024

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments and Hedging Activities Disclosure

7. Derivative Instruments and Hedging Activities

BPLP’s agreements with derivative counterparties contain provisions whereby if BPLP defaults on the underlying indebtedness, including defaults where repayment of the indebtedness has not been accelerated by the lender, then BPLP could also be declared in default of the swap derivative obligation. As of September 30, 2024, the Company had not posted any collateral related to the agreements.

Effective Hedge Instruments

BPLP assesses the effectiveness of its derivatives both at inception and on an ongoing basis. If the hedges are deemed to be effective, the fair value is recorded in “Accumulated other comprehensive loss” in the Company’s Consolidated Balance Sheets and is subsequently reclassified into “Interest expense” in the Company’s Consolidated Statements of Operations in the period that the hedged forecasted transactions affect earnings. BPLP’s derivative financial instruments are cash flow hedges that are designated as effective hedges, and they are carried at their estimated fair value on a recurring basis (See Note 2). The Company did not incur ineffectiveness during the three and nine months ended September 30, 2024.

BPLP’s and SMBP LLC’s derivative contracts consisted of the following at September 30, 2024 (dollars in thousands):


Derivative Instrument	Aggregate Notional Amount				Strike Rate Range					Balance Sheet Location
			Effective Date	Maturity Date	Low			High			Fair Value
BPLP:
Interest Rate Swaps	$	600,000	December 15, 2023	October 26, 2028	3.790	%	—	3.798	%	Other liabilities	$	(12,600)
Interest Rate Swaps	100,000		September 27, 2024	April 1, 2025	2.688	%	—	2.688	%	Prepaid expenses and other assets	799
	700,000										(11,801)
SMBP LLC (1)
Interest Rate Swaps	200,000		December 14, 2023	April 1, 2025	2.661	%	—	2.688	%	Prepaid expenses and other assets	1,610
	$	900,000									$	(10,191)

_______________

(1)A consolidated subsidiary of the Company that is the borrower under the mortgage loan collateralized by its Santa Monica Business Park property.

The following table presents the location in the financial statements of the gains or (losses) recognized as a result of the Company’s cash flow hedges for the three and nine months ended September 30, 2024 and 2023 (in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (1)	$	(32,263)	$	5,459	$	(14,976)	$	13,886
Amount of gain (loss) related to the effective portion subsequently reclassified to earnings (2)	$	3,077	$	1,677	$	9,518	$	5,026
Amount of gain (loss) related do the ineffective portion and amount excluded from effectiveness testing	$	—	$	—	$	—	$	—

_______________

(1)Includes the Company’s share of gain (loss) related to the effective portion of derivatives outstanding at its unconsolidated joint venture properties.

(2)Includes amounts from previous interest rate programs.

BPLP has formally documented all of its relationships between hedge instruments and hedging items, as well as its risk-management objectives and strategy for undertaking various hedge transactions. While management believes its judgments are reasonable, a change in a derivative's effectiveness as a hedge could materially affect expenses, net income (loss) and equity.

Ineffective Hedging Instruments

During the year ended December 31, 2023, to satisfy a lender requirement, the Company entered into two agreements with the same third-party to purchase and sell a $600.0 million interest rate cap. The Company did not elect hedge accounting, and as such, any change in market value will be recognized in Gain (losses) from interest rate contracts in the Consolidated Statement of Operations. For the three and nine months ended September 30, 2024 and 2023, the Company recognized no impact to its Consolidated Statement of Operations from entering into these agreements.

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Unsecured Senior Notes (Narrative) (Details) - USD ($) $ in Thousands				9 Months Ended
	Aug. 26, 2024	Feb. 01, 2024	Oct. 26, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Proceeds from Secured Notes Payable			$ 600,000
Repayments of Unsecured Debt				$ 700,000	$ 500,000
Proceeds from unsecured senior notes				849,671	747,727
Boston Properties Limited Partnership
Debt Instrument [Line Items]
Repayments of Unsecured Debt				700,000	500,000
Proceeds from unsecured senior notes				849,671	$ 747,727
Senior Notes \| Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt				10,700,000
3.916% unsecured senior notes \| Senior Notes \| Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt		$ 700,000
Debt Instrument, Interest Rate, Stated Percentage		3.80%
Repayments of Unsecured Debt		$ 713,300
Debt Instrument, Increase, Accrued Interest		$ 13,300
Five point Eight Four Two Percent \| Senior Notes \| Boston Properties Limited Partnership
Debt Instrument [Line Items]
Debt	$ 850,000			$ 850,000
Debt Instrument, Interest Rate, Stated Percentage	5.75%			5.75%
Debt Instrument, Interest Rate, Effective Percentage	5.842%			5.842%
Senior Notes Pricing	99.961%
Proceeds from unsecured senior notes	$ 841,900

Derivative Instruments and Hedging Activities Gain (Loss) (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Derivative Instruments, Gain (Loss) [Line Items]

Amount of gain (loss) related to the effective portion recognized in other comprehensive income

^[1]

$ (32,263)

$ 5,459

$ (14,976)

$ 13,886

Amount of gain (loss) related to the effective portion subsequently reclassified to earnings

^[2]

3,077

1,677

9,518

5,026

Amount of gain (loss) relate do the ineffective portion and amount excluded from effectiveness testing

$ 0

[1]	Includes the Company’s share of gain (loss) related to the effective portion of derivatives outstanding at its unconsolidated joint venture properties.
[2]	Includes amounts from previous interest rate programs.

Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Dividends In Excess Of Earnings [Member]	Treasury Stock, at cost [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]	Noncontrolling interest - property partnerships [Member]
Equity, shares at Dec. 31, 2022		156,758,000
Equity, value at Dec. 31, 2022	$ 8,363,819	$ 1,568	$ 6,539,147	$ (391,356)	$ (2,722)	$ (13,718)	$ 683,583	$ 1,547,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		100,000
Redemption of operating partnership units to common stock, value	0	$ 1	3,713				(3,714)
Allocated net income for the period	138,269			70,290			8,642	59,337
Dividends declared	(516,247)			(461,209)			(55,038)
Shares issued pursuant to stock purchase plan, shares		19,000
Shares issued pursuant to stock purchase plan, value	1,156		1,156
Net activity from stock option and incentive plan, shares		62,000
Net activity from stock option and incentive plan, value	45,847		3,759				42,088
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	30,190							30,190
Distributions to noncontrolling interests in property partnerships	(48,370)							(48,370)
Effective portion of interest rate contracts	13,886					12,461	1,425
Amortization of interest rate contracts	5,026					4,123	471	432
Reallocation of noncontrolling interest	0		20,870				(20,870)
Equity, shares at Sep. 30, 2023		156,939,000
Equity, value at Sep. 30, 2023	8,033,576	$ 1,569	6,568,645	(782,275)	(2,722)	2,866	656,587	1,588,906
Equity, shares at Jun. 30, 2023		156,854,000
Equity, value at Jun. 30, 2023	8,286,543	$ 1,569	6,561,161	(516,550)	(2,722)	(3,406)	689,123	1,557,368
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		79,000
Redemption of operating partnership units to common stock, value	0	$ 0	2,920				(2,920)
Allocated net income for the period	(103,543)			(111,925)			(12,527)	20,909
Dividends declared	(172,101)			(153,800)			(18,301)
Shares issued pursuant to stock purchase plan, shares		10,000
Shares issued pursuant to stock purchase plan, value	570		570
Net activity from stock option and incentive plan, shares		(4,000)
Net activity from stock option and incentive plan, value	4,486		421				4,065
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	22,635							22,635
Distributions to noncontrolling interests in property partnerships	(12,150)							(12,150)
Effective portion of interest rate contracts	5,459					4,896	563
Amortization of interest rate contracts	1,677					1,376	157	144
Reallocation of noncontrolling interest	0		3,573				(3,573)
Equity, shares at Sep. 30, 2023		156,939,000
Equity, value at Sep. 30, 2023	$ 8,033,576	$ 1,569	6,568,645	(782,275)	(2,722)	2,866	656,587	1,588,906
Equity, shares at Dec. 31, 2023	156,940,866	156,941,000
Equity, value at Dec. 31, 2023	$ 8,183,981	$ 1,569	6,715,149	(816,152)	(2,722)	(21,147)	666,580	1,640,704
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		952,000
Redemption of operating partnership units to common stock, value	0	$ 11	33,735				(33,746)
Allocated net income for the period	322,005			243,126			28,596	50,283
Dividends declared	(518,376)			(462,684)			(55,692)
Shares issued pursuant to stock purchase plan, shares		17,000
Shares issued pursuant to stock purchase plan, value	1,141		1,141
Net activity from stock option and incentive plan, shares		70,000
Net activity from stock option and incentive plan, value	34,523		2,988				31,535
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	306,147		70,941					235,206
Distributions to noncontrolling interests in property partnerships	(52,353)							(52,353)
Effective portion of interest rate contracts	(14,976)					(13,429)	(1,547)
Amortization of interest rate contracts	9,518					8,148	938	432
Reallocation of noncontrolling interest	$ 0		(1,465)				1,465
Equity, shares at Sep. 30, 2024	157,979,898	157,980,000
Equity, value at Sep. 30, 2024	$ 8,271,610	$ 1,580	6,822,489	(1,035,710)	(2,722)	(26,428)	638,129	1,874,272
Equity, shares at Jun. 30, 2024		157,098,000
Equity, value at Jun. 30, 2024	8,282,327	$ 1,571	6,768,686	(964,518)	(2,722)	(155)	677,789	1,801,676
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of operating partnership units to common stock, shares		875,000
Redemption of operating partnership units to common stock, value	0	$ 9	30,983				(30,992)
Allocated net income for the period	108,452			83,628			9,587	15,237
Dividends declared	(172,806)			(154,820)			(17,986)
Shares issued pursuant to stock purchase plan, shares		9,000
Shares issued pursuant to stock purchase plan, value	541		541
Net activity from stock option and incentive plan, shares		(2,000)
Net activity from stock option and incentive plan, value	1,452		(1,773)				3,225
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	95,724		23,615					72,109
Distributions to noncontrolling interests in property partnerships	(14,894)							(14,894)
Effective portion of interest rate contracts	(32,263)					(28,910)	(3,353)
Amortization of interest rate contracts	3,077					2,637	296	144
Reallocation of noncontrolling interest	$ 0		437				(437)
Equity, shares at Sep. 30, 2024	157,979,898	157,980,000
Equity, value at Sep. 30, 2024	$ 8,271,610	$ 1,580	$ 6,822,489	$ (1,035,710)	$ (2,722)	$ (26,428)	$ 638,129	$ 1,874,272

Stock Option and Incentive Plan	9 Months Ended
Stock Option and Incentive Plan	Sep. 30, 2024
Share-Based Payment Arrangement [Abstract]
Stock Option and Incentive Plan	13. Stock Option and Incentive Plan On January 25, 2024, the Compensation Committee of BXP’s Board of Directors approved the grant of 2024 Multi-Year Long-Term Incentive Program (the “2024 MYLTIP”) awards under the Boston Properties, Inc. 2021 Stock Incentive Plan (the “2021 Plan”) to certain executive officers of BXP. The 2024 MYLTIP awards consists of three components. Two of the components, each weighted 40%, utilize BXP’s TSR over a three-year measurement period as the performance metrics and the third component utilizes a leverage ratio as the performance metric. Earned awards will range from zero to a maximum of 330,479 LTIP Units depending on BXP’s performance under the three components, with a target of approximately 165,240 LTIP Units. Under ASC 718 “Compensation - Stock Compensation,” the 2024 MYLTIP awards have an aggregate value of approximately $11.1 million. On February 1, 2024, the measurement period for the Company’s 2021 MYLTIP awards ended and, based on BXP’s absolute and relative TSR performance, the final payout was determined to be 112% of target, or an aggregate of approximately $12.6 million (after giving effect to employee separations). As a result, an aggregate of 155,625 2021 MYLTIP Units that had been previously granted were automatically forfeited. During the nine months ended September 30, 2024, BXP issued 83,316 shares of restricted common stock and BPLP issued 451,044 LTIP Units and 330,479 2024 MYLTIP Units to employees and non-employee directors under the 2021 Plan. Employees and non-employee directors paid $0.01 per share of restricted common stock and $0.25 per LTIP Unit and 2024 MYLTIP Unit. When issued, LTIP Units are not economically equivalent in value to a share of Common Stock, but over time can increase in value to one-for-one parity with Common Stock if there is sufficient appreciation in the value of the Company’s assets. The aggregate value of the LTIP Units is included in noncontrolling interests in the Consolidated Balance Sheets of BXP and BPLP. A substantial majority of the grants of restricted common stock and LTIP Units to employees vest in four equal annual installments. Restricted common stock is measured at fair value on the date of grant based on the number of shares granted and the closing price of BXP’s Common Stock on the date of grant as quoted on the New York Stock Exchange. Such value is recognized as an expense ratably over the corresponding employee service period. The shares of restricted common stock granted during the nine months ended September 30, 2024 were valued at approximately $5.3 million. The LTIP Units granted were valued at approximately $26.7 million using a Monte Carlo simulation method model. Because the 2012 OPP Units and 2013 - 2024 MYLTIP Units are subject to both a service condition and a market condition, the Company recognizes the related compensation expense under the graded vesting attribution method. Under the graded vesting attribution method, each portion of the award that vests at a different date is accounted for as a separate award and recognized over the period appropriate to that portion so that the compensation cost for each portion should be recognized in full by the time that portion vests. The Company recognizes forfeitures as they occur on its awards of stock-based compensation. Dividends paid on both vested and unvested shares of restricted stock are charged directly to Dividends in Excess of Earnings in BXP, Inc.’s Consolidated Balance Sheets and Partners’ Capital in Boston Properties Limited Partnership’s Consolidated Balance Sheets. Aggregate stock-based compensation expense associated with restricted stock, LTIP Units and MYLTIP Units was approximately $4.0 million and $4.8 million for the three months ended September 30, 2024 and 2023, respectively, and $38.5 million and $45.7 million for the nine months ended September 30, 2024 and 2023, respectively. At September 30, 2024, there was (1) an aggregate of approximately $25.4 million of unrecognized compensation expense related to unvested restricted stock and LTIP Units and (2) an aggregate of approximately $(40,000) of unrecognized compensation expense related to unvested 2022 - 2024 MYLTIP Units that is expected to be recognized over a weighted-average period of approximately 2.5 years.

Unsecured Credit Facility (Details) - USD ($) $ in Thousands	Jun. 15, 2021	Sep. 30, 2024	Apr. 29, 2024	Apr. 17, 2024	Dec. 31, 2023	Sep. 28, 2023
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date	Jun. 15, 2026
Long-term Line of Credit		$ 0			$ 0
Commercial Paper
Line of Credit Facility [Line Items]
Commercial Paper, Maximum Borrowing Capacity				$ 500,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,500,000		$ 2,000,000			$ 1,815,000
Line of Credit, Additional Borrowing Capacity	$ 500,000
Long-term Line of Credit		$ 0

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

Segment Information (Tables)

9 Months Ended

Sep. 30, 2024

Segment Reporting [Abstract]

Schedule Of Reconciliation Of Net Operating Income To Net Income

BXP


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Net income (loss) attributable to BXP, Inc.	$	83,628	$	(111,826)	$	243,126	$	70,290
Add:
Noncontrolling interest—common units of the Operating Partnership	9,587		(12,626)		28,596		8,642
Noncontrolling interests in property partnerships	15,237		20,909		50,283		59,337
Interest expense	163,194		147,812		474,727		424,492
Impairment loss	—		—		13,615		—


Net operating income from unconsolidated joint ventures	31,919		39,165		98,936		122,175
Depreciation and amortization expense	222,890		207,435		661,148		618,746
Transaction costs	188		751		890		1,970
Payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
General and administrative expense	33,352		31,410		127,479		131,387
Less:
Net operating income attributable to noncontrolling interests in property partnerships	44,487		50,047		138,448		145,102
Unrealized gain (loss) on non-real estate investment	94		(51)		548		332
Gains (losses) from investments in securities	2,198		(925)		4,785		2,311

Interest and other income (loss)	14,430		20,715		39,747		48,999
Gains on sales of real estate	517		517		517		517
Income (loss) from unconsolidated joint ventures	(7,011)		(247,556)		6,376		(261,793)

Direct reimbursements of payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
Development and management services revenue	6,770		9,284		19,276		28,122
Company’s share of Net Operating Income	$	498,510	$	490,999	$	1,489,103	$	1,473,449

BPLP


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Net income (loss) attributable to Boston Properties Limited Partnership	$	94,919	$	(122,696)	$	276,826	$	84,232
Add:
Noncontrolling interests in property partnerships	15,237		20,909		50,283		59,337
Interest expense	163,194		147,812		474,727		424,492


Impairment loss	—		—		13,615		—
Net operating income from unconsolidated joint ventures	31,919		39,165		98,936		122,175
Depreciation and amortization expense	221,186		205,679		656,044		613,446
Transaction costs	188		751		890		1,970
Payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
General and administrative expense	33,352		31,410		127,479		131,387
Less:
Net operating income attributable to noncontrolling interests in property partnerships	44,487		50,047		138,448		145,102
Unrealized gain (loss) on non-real estate investment	94		(51)		548		332
Gains (losses) from investments in securities	2,198		(925)		4,785		2,311

Interest and other income (loss)	14,430		20,715		39,747		48,999
Gains on sales of real estate	517		517		517		517
Income (loss) from unconsolidated joint ventures	(7,011)		(247,556)		6,376		(261,793)

Direct reimbursements of payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
Development and management services revenue	6,770		9,284		19,276		28,122
Company’s share of Net Operating Income	$	498,510	$	490,999	$	1,489,103	$	1,473,449

Schedule Of Segment Information By Geographic Area And Property Type

Information by geographic area and property type (dollars in thousands):

For the three months ended September 30, 2024:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	300,613		$	18,661		$	258,295		$	128,929		$	10,821		$	104,290		$	821,609
Residential	4,219			—			—			3,152			—			4,746			12,117
Hotel	15,082			—			—			—			—			—			15,082
Total	319,914			18,661			258,295			132,081			10,821			109,036			848,808
% of Grand Totals	37.69		%	2.20		%	30.43		%	15.56		%	1.27		%	12.85		%	100.00		%
Rental Expenses:
Office	107,876			7,344			111,419			52,410			3,382			39,478			321,909
Residential	1,621			—			—			2,346			—			2,021			5,988
Hotel	9,833			—			—			—			—			—			9,833
Total	119,330			7,344			111,419			54,756			3,382			41,499			337,730
% of Grand Totals	35.34		%	2.17		%	32.99		%	16.21		%	1.00		%	12.29		%	100.00		%
Net operating income	$	200,584		$	11,317		$	146,876		$	77,325		$	7,439		$	67,537		$	511,078
% of Grand Totals	39.25		%	2.21		%	28.74		%	15.13		%	1.46		%	13.21		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(10,823)			—			(33,664)			—			—			—			(44,487)
Add: Company’s share of net operating income from unconsolidated joint ventures	9,099			6,835			3,472			4,285			1,899			6,329			31,919
Company’s share of net operating income	$	198,860		$	18,152		$	116,684		$	81,610		$	9,338		$	73,866		$	498,510
% of Grand Totals	39.89		%	3.64		%	23.41		%	16.37		%	1.87		%	14.82		%	100.00		%

_______________

(1)Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

For the three months ended September 30, 2023:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	276,153		$	—		$	268,680		$	135,839		$	13,660		$	91,488		$	785,820
Residential	4,198			—			—			3,214			—			4,377			11,789
Hotel	13,484			—			—			—			—			—			13,484
Total	293,835			—			268,680			139,053			13,660			95,865			811,093
% of Grand Totals	36.23		%	—		%	33.13		%	17.14		%	1.68		%	11.82		%	100.00		%
Rental Expenses:
Office	97,358			—			107,462			50,450			2,971			36,213			294,454
Residential	1,629			—			—			2,221			—			1,888			5,738
Hotel	9,020			—			—			—			—			—			9,020
Total	108,007			—			107,462			52,671			2,971			38,101			309,212
% of Grand Totals	34.94		%	—		%	34.75		%	17.03		%	0.96		%	12.32		%	100.00		%
Net operating income	$	185,828		$	—		$	161,218		$	86,382		$	10,689		$	57,764		$	501,881
% of Grand Totals	37.03		%	—		%	32.12		%	17.21		%	2.13		%	11.51		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(11,786)			—			(38,261)			—			—			—			(50,047)
Add: Company’s share of net operating income from unconsolidated joint ventures	7,946			12,508			3,938			4,023			1,874			8,876			39,165
Company’s share of net operating income	$	181,988		$	12,508		$	126,895		$	90,405		$	12,563		$	66,640		$	490,999
% of Grand Totals	37.07		%	2.55		%	25.84		%	18.41		%	2.56		%	13.57		%	100.00		%

_______________

For the nine months ended September 30, 2024:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	866,431		$	57,534		$	780,909		$	393,252		$	32,251		$	312,298		$	2,442,675
Residential	12,687			—			—			10,428			—			13,912			37,027
Hotel	38,080			—			—			—			—			—			38,080
Total	917,198			57,534			780,909			403,680			32,251			326,210			2,517,782
% of Grand Totals	36.42		%	2.29		%	31.02		%	16.03		%	1.28		%	12.96		%	100.00		%
Rental Expenses:
Office	321,955			20,678			327,376			148,020			9,753			118,285			946,067
Residential	4,757			—			—			6,733			—			5,923			17,413
Hotel	25,687			—			—			—			—			—			25,687
Total	352,399			20,678			327,376			154,753			9,753			124,208			989,167
% of Grand Totals	35.62		%	2.09		%	33.10		%	15.64		%	0.99		%	12.56		%	100.00		%
Net operating income	$	564,799		$	36,856		$	453,533		$	248,927		$	22,498		$	202,002		$	1,528,615
% of Grand Totals	36.96		%	2.41		%	29.67		%	16.28		%	1.47		%	13.21		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(32,803)			—			(105,645)			—			—			—			(138,448)
Add: Company’s share of net operating income from unconsolidated joint ventures	26,547			21,118			12,614			13,850			5,713			19,094			98,936
Company’s share of net operating income	$	558,543		$	57,974		$	360,502		$	262,777		$	28,211		$	221,096		$	1,489,103
% of Grand Totals	37.51		%	3.89		%	24.21		%	17.65		%	1.89		%	14.85		%	100.00		%

_______________

For the nine months ended September 30, 2023:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	815,568		$	—		$	789,851		$	408,173		$	44,978		$	272,872		$	2,331,442
Residential	12,371			—			—			10,720			—			12,677			35,768
Hotel	35,554			—			—			—			—			—			35,554
Total	863,493			—			789,851			418,893			44,978			285,549			2,402,764
% of Grand Totals	35.95		%	—		%	32.87		%	17.43		%	1.87		%	11.88		%	100.00		%
Rental Expenses:
Office	293,004			—			312,895			144,732			9,013			105,908			865,552
Residential	4,782			—			—			6,609			—			5,593			16,984
Hotel	23,852			—			—			—			—			—			23,852
Total	321,638			—			312,895			151,341			9,013			111,501			906,388
% of Grand Totals	35.49		%	—		%	34.52		%	16.70		%	0.99		%	12.30		%	100.00		%
Net operating income	$	541,855		$	—		$	476,956		$	267,552		$	35,965		$	174,048		$	1,496,376
% of Grand Totals	36.22		%	—		%	31.87		%	17.88		%	2.40		%	11.63		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(33,946)			—			(111,156)			—			—			—			(145,102)
Add: Company’s share of net operating income from unconsolidated joint ventures	25,294			38,501			10,951			10,819			5,598			31,012			122,175
Company’s share of net operating income	$	533,203		$	38,501		$	376,751		$	278,371		$	41,563		$	205,060		$	1,473,449
% of Grand Totals	36.19		%	2.61		%	25.57		%	18.89		%	2.82		%	13.92		%	100.00		%

_______________

Stockholders' Equity / Partners' Capital Dividends / Distributions (Details) - $ / shares	Jul. 31, 2024	Apr. 30, 2024	Jan. 30, 2024	Oct. 31, 2023	Jul. 31, 2023	Apr. 28, 2023	Jan. 30, 2023	Sep. 09, 2024
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit								$ 0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98
Boston Properties Limited Partnership
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit								0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Op units and LTIP units
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit								0.98
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Unvested MYLTIP Units [Member]
Dividends / Distributions [Line Items]
Dividends Payable, Amount Per Share / Unit								$ 0.098
Common Stock / Unit, Dividends / Distributions, Per Share / Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098

(Common Units) (Narrative) (Details) $ / shares in Units, $ in Thousands		9 Months Ended
	Feb. 01, 2024 USD ($) shares	Sep. 30, 2024 USD ($) yr $ / shares shares	Dec. 31, 2023 USD ($)
Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount \| $		$ 1,500,501	$ 1,347,575
MYLTIP \| Boston Properties Limited Partnership
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Vesting Period		3 years
Unvested MYLTIP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
unvested MYLTIP distributions as compared to total distributions (percentage)		10.00%
MYLTIP 2021
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target	112.00%
Value of MYLTIP Awards \| $	$ 12,600
Forfeitures, in units	155,625
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares)		951,881
Restriction on redemption of OP Unit to Common Stock (in years) \| yr		1
Redemption of OP Unit equivalent to Common Stock (in shares)		1
Redeemable Noncontrolling Interest, Equity, Preferred, Carrying Amount \| $		$ 1,500,000
Closing price of common stock (in dollars per share) \| $ / shares		$ 80.46
Vested 2012 OPP units and MYLTIPS
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares)		105,814

Stockholders' Equity / Partners' Capital

9 Months Ended

Sep. 30, 2024

Equity [Abstract]

Stockholders' Equity / Partners' Capital

10. Stockholders’ Equity / Partners’ Capital

As of September 30, 2024, BXP had 157,979,898 shares of Common Stock outstanding.

As of September 30, 2024, BXP owned 1,762,427 general partnership units and 156,217,471 limited partnership units in BPLP.

On May 17, 2023, BXP renewed its “at the market” (“ATM”) stock offering program through which it may sell from time to time up to an aggregate of $600.0 million of its Common Stock through sales agents over a three-year period. Under the ATM stock offering program, BXP may also engage in forward sale transactions with affiliates of certain sales agents for the sale of its Common Stock on a forward basis. This program replaced BXP’s prior $600.0 million ATM stock offering program that was scheduled to expire on May 22, 2023. BXP intends to use the net proceeds from any offering for general business purposes, which may include investment opportunities and debt reduction. No shares of Common Stock have been issued under this ATM stock offering program.

During the nine months ended September 30, 2024, BXP issued 951,881 shares of Common Stock in connection with the redemption of an equal number of redeemable OP Units from limited partners.

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2024 and during the nine months ended September 30, 2023:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
September 30, 2024	October 31, 2024	$0.98	$0.98
June 28, 2024	July 31, 2024	$0.98	$0.98
March 28, 2024	April 30, 2024	$0.98	$0.98
December 29, 2023	January 30, 2024	$0.98	$0.98
September 29, 2023	October 31, 2023	$0.98	$0.98
June 30, 2023	July 31, 2023	$0.98	$0.98
March 31, 2023	April 28, 2023	$0.98	$0.98
December 30, 2022	January 30, 2023	$0.98	$0.98

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-16

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

Real Estate Asset Acquisition (Details) - 901 New York Avenue $ in Thousands	Jan. 08, 2024 USD ($)
Asset Acquisition [Line Items]
Land	$ 65,808
Building and improvements	56,882
Tenant Improvements	16,088
Net Assets Acquired	220,015
Mortgages [Member]
Asset Acquisition [Line Items]
Liabilities, Fair Value Adjustment	8,374
In-Place Lease Intangibles
Asset Acquisition [Line Items]
Lease Intangibles	72,621
Above Market Lease Intangibles [Member]
Asset Acquisition [Line Items]
Lease Intangibles	2,757
Below Market Lease [Member]
Asset Acquisition [Line Items]
Lease Intangibles	$ (2,515)

Noncontrolling Interests Common Units Distributions (Details) - $ / shares	Jul. 31, 2024	Apr. 30, 2024	Jan. 30, 2024	Oct. 31, 2023	Jul. 31, 2023	Apr. 28, 2023	Jan. 30, 2023	Sep. 09, 2024
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit								$ 0.98
Dividends, Per Unit, Cash Paid	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98	$ 0.98
Boston Properties Limited Partnership
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit								0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Op units and LTIP units
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit								0.98
Dividends, Per Unit, Cash Paid	0.98	0.98	0.98	0.98	0.98	0.98	0.98
Boston Properties Limited Partnership \| Unvested MYLTIP Units [Member]
Dividends Payable [Line Items]
Distributions Payable, Amount Per Unit								$ 0.098
Dividends, Per Unit, Cash Paid	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098	$ 0.098

Debt

9 Months Ended

Sep. 30, 2024

Debt Disclosure [Abstract]

Debt Disclosure [Text Block]

6. Debt

Mortgage Notes Payable

On January 8, 2024, the Company acquired its joint venture partner’s 50% economic ownership interest in the joint venture that owns 901 New York Avenue located in Washington, DC (See Note 3). The property is subject to existing mortgage indebtedness. At acquisition, the mortgage loan had an outstanding principal balance of approximately $207.1 million, bore interest at 3.61% per annum and was scheduled to mature on January 5, 2025. The mortgage loan was recorded at a fair value of approximately $198.7 million. On January 11, 2024, the Company modified the mortgage loan to provide for two extension options totaling five years of additional term, each subject to certain conditions.

Unsecured Senior Notes

The following summarizes the unsecured senior notes outstanding as of September 30, 2024 (dollars in thousands):


	Coupon/Stated Rate		Effective Rate(1)		Principal Amount		Maturity Date(2)
7 Year Unsecured Senior Notes	3.200	%	3.350	%	$	850,000	January 15, 2025
10 Year Unsecured Senior Notes	3.650	%	3.766	%	1,000,000		February 1, 2026
10 Year Unsecured Senior Notes	2.750	%	3.495	%	1,000,000		October 1, 2026
5 Year Unsecured Senior Notes	6.750	%	6.924	%	750,000		December 1, 2027
10 Year Unsecured Senior Notes	4.500	%	4.628	%	1,000,000		December 1, 2028
10 Year Unsecured Senior Notes	3.400	%	3.505	%	850,000		June 21, 2029
10.5 Year Unsecured Senior Notes	2.900	%	2.984	%	700,000		March 15, 2030
10.75 Year Unsecured Senior Notes	3.250	%	3.343	%	1,250,000		January 30, 2031
11 Year Unsecured Senior Notes	2.550	%	2.671	%	850,000		April 1, 2032
12 Year Unsecured Senior Notes	2.450	%	2.524	%	850,000		October 1, 2033
10.7 Year Unsecured Senior Notes	6.500	%	6.619	%	750,000		January 15, 2034
10 Year Unsecured Senior Notes	5.750	%	5.842	%	850,000		January 15, 2035
Total principal					10,700,000
Less:
Net unamortized discount					11,580
Deferred financing costs, net					46,387
Total					$	10,642,033

_______________

(1)Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

(2)No principal amounts are due prior to maturity.

On February 1, 2024, BPLP repaid $700.0 million in aggregate principal amount of its 3.800% senior notes due February 1, 2024. The repayment was completed with available cash and the $600.0 million proceeds from the mortgage loan entered into on October 26, 2023. The repayment price was approximately $713.3 million, which was equal to the stated principal plus approximately $13.3 million of accrued and unpaid interest to, but not including, the repayment date. Excluding the accrued and unpaid interest, the repayment price was equal to the principal amount being repaid.

On August 26, 2024, BPLP completed a public offering of $850.0 million in aggregate principal amount of its 5.750% unsecured senior notes due 2035. The notes were priced at 99.961% of the principal amount to yield an effective rate (including financing fees) of approximately 5.842% per annum to maturity. The notes will mature on January 15, 2035, unless earlier redeemed. The aggregate net proceeds from the offering were approximately $841.9 million after deducting underwriting discounts and transaction expenses.

Unsecured Credit Facility

BPLP’s unsecured revolving credit facility (the “2021 Credit Facility”) provides for borrowings of up to $2.0 billion, as described below in this Note 6, through BPLP’s revolving facility, subject to customary conditions. The 2021 Credit Facility matures on June 15, 2026 and includes a sustainability-linked pricing component. Under the 2021 Credit Facility, BPLP had the option to increase the original total commitment of $1.5 billion by up to an additional $500.0 million by increasing the amount of the Revolving Facility and/or by incurring one or more term loans, in each case, subject to syndication of the increase and other conditions (the “Accordion Option”). On September 28, 2023, BPLP exercised a portion of the Accordion Option which increased the then maximum borrowing amount under the 2021 Credit Facility from $1.5 billion to $1.815 billion. On April 29, 2024, BPLP exercised the remainder of the Accordion Option and further increased the maximum borrowing amount under the 2021 Credit Facility to $2.0 billion. All other terms of the 2021 Credit Facility remain unchanged.

At September 30, 2024, BPLP had no amount outstanding under the 2021 Credit Facility. The 2021 Credit Facility is used as a backstop for BPLP’s $500.0 million unsecured commercial paper program (See “Unsecured Commercial Paper” below). As such, BPLP intends to maintain, at a minimum, availability under the 2021 Credit Facility in an amount equal to the amount of unsecured commercial paper notes outstanding.

Unsecured Term Loans

On January 4, 2023, BPLP entered into a credit agreement that provided for a $1.2 billion unsecured term loan facility (the “2023 Unsecured Term Loan”). Upon entry into the credit agreement, BPLP exercised its option to draw $1.2 billion under the 2023 Unsecured Term Loan.

On April 29, 2024, BPLP repaid $500.0 million of the outstanding balance under the 2023 Unsecured Term Loan from the proceeds of its unsecured commercial paper program (See “Unsecured Commercial Paper” below). At September 30, 2024, BPLP had $700.0 million of principal outstanding under the 2023 Unsecured Term Loan.

Under the credit agreement governing the 2023 Unsecured Term Loan, BPLP may, at any time prior to the maturity date, increase total commitments by up to an additional $300.0 million in aggregate principal amount by increasing the existing 2023 Unsecured Term Loan or incurring one or more additional term loans, in each case, subject to syndication of the increase and other conditions. The 2023 Unsecured Term Loan had an initial maturity date of May 16, 2024, with one 12-month extension option, subject to customary conditions. On May 16, 2024, BPLP exercised its option to extend the maturity date of the 2023 Unsecured Term Loan to May 16, 2025. All other terms of the 2023 Unsecured Term Loan remain unchanged.

On September 27, 2024, BPLP entered into a credit agreement that provides for a $100.0 million unsecured term loan facility (the “2024 Unsecured Term Loan”) with a lender (the “Lender”) under the mortgage loan collateralized by the Company’s Santa Monica Business Park properties located in Santa Monica, California (the “SMBP Loan”). Upon entry into the credit agreement, BPLP exercised its option to draw $100.0 million under the 2024 Unsecured Term Loan. The proceeds were used to repay the portion of the SMBP Loan held by the Lender. After the repayment, the SMBP Loan had a remaining principal balance of $200.0 million (See Note 14). The 2024 Unsecured Term Loan matures on September 26, 2025 with three, one-year extension options, subject to customary conditions.

At BPLP’s option, loans under the 2024 Unsecured Term Loan will bear interest at a rate per annum equal to (1) a base rate equal to the highest of (a) zero, (b) Prime Rate, (c) the Federal Funds effective rate plus 0.50%, and (d) Term SOFR for a one-month period plus 1.10%, in each case, plus a margin ranging from 0 to 60 basis points based on BPLP’s credit rating; or (2) a rate equal to adjusted Term SOFR or Daily Simple SOFR with a one-month period plus a margin ranging from 75 to 160 basis points based on BPLP’s credit rating.

Based on BPLP’s September 30, 2024 credit rating, the 2024 Unsecured Term Loan bears interest at a rate equal to Daily Simple SOFR plus 1.05% per annum. The 2024 Unsecured Term Loan is subject to an existing interest rate swap to fix Daily Simple SOFR at a fixed rate of approximately 2.688% per annum for a period that ends on April 1, 2025 (See Note 7). At September 30, 2024, BPLP had $100.0 million of principal outstanding under the 2024 Unsecured Term Loan.

The 2023 and 2024 Unsecured Term Loans contain customary representations and warranties, affirmative and negative covenants and events of default provisions, including the failure to pay indebtedness, breaches of covenants and bankruptcy and other insolvency events, which could result in the acceleration of the obligation to repay any outstanding amount under the 2023 and 2024 Unsecured Term Loans. Among other covenants, the 2023 and 2024 Unsecured Term Loans require that BPLP maintain on an ongoing basis: (1) a leverage ratio not to exceed 60%, however, the leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within one year, (2) a secured debt leverage ratio not to exceed 55%, (3) a fixed charge coverage ratio of at least 1.40 to 1.00, (4) an unsecured debt leverage ratio not to exceed 60%, however, the unsecured debt leverage ratio may increase to no greater than 65% provided that it is reduced to 60% within one year, (5) an unsecured debt interest coverage ratio of at least 1.75 to 1.00 and (6) limitations on permitted investments. At September 30, 2024, BPLP was in compliance with each of these financial and other covenant requirements.

Unsecured Commercial Paper

On April 17, 2024, BPLP established an unsecured commercial paper program. Under the terms of the program, BPLP may issue, from time to time, unsecured commercial paper notes up to a maximum aggregate amount outstanding at any one time of $500.0 million with varying maturities of up to one year. Amounts available

under the unsecured commercial paper program may be borrowed, repaid, and re-borrowed from time to time. The notes are sold in private placements and rank pari passu with all of BPLP’s other unsecured senior indebtedness, including its outstanding senior notes. The commercial paper program is backstopped by available capacity under the 2021 Credit Facility. At September 30, 2024, BPLP had an aggregate of $500.0 million of unsecured commercial paper notes outstanding that bore interest at a weighted-average rate of approximately 5.22% per annum and had a weighted-average maturity of 34 days from the issuance date.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481544/470-10-50-6

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477092/405-40-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-Subparagraph (a)(3)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/470/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Schedule of Unsecured Senior Notes (Details) - USD ($)
$ in Thousands

Sep. 30, 2024

Aug. 26, 2024

Dec. 31, 2023

Debt Instrument [Line Items]

Senior Notes

$ 10,642,033

$ 10,491,617

Boston Properties Limited Partnership

Debt Instrument [Line Items]

Senior Notes

10,642,033

$ 10,491,617

Boston Properties Limited Partnership | Senior Notes

Debt Instrument [Line Items]

Debt

10,700,000

Debt Instrument, Unamortized Discount

11,580

Debt Issuance Costs, Net

$ 46,387

Boston Properties Limited Partnership | Senior Notes | 3.350% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.20%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.35%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Jan. 15, 2025

Boston Properties Limited Partnership | Senior Notes | 3.766% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.65%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.766%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Feb. 01, 2026

Boston Properties Limited Partnership | Senior Notes | 3.495% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.75%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.495%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Oct. 01, 2026

Boston Properties Limited Partnership | Senior Notes | 6.924% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

6.75%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

6.924%

Debt

$ 750,000

Long-term Debt, Maturity Date

^[2]

Dec. 01, 2027

Boston Properties Limited Partnership | Senior Notes | 4.628% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

4.50%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

4.628%

Debt

$ 1,000,000

Long-term Debt, Maturity Date

^[2]

Dec. 01, 2028

Boston Properties Limited Partnership | Senior Notes | 3.505% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.40%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.505%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Jun. 21, 2029

Boston Properties Limited Partnership | Senior Notes | 2.984% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.90%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.984%

Debt

$ 700,000

Long-term Debt, Maturity Date

^[2]

Mar. 15, 2030

Boston Properties Limited Partnership | Senior Notes | 3.343 % unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

3.25%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

3.343%

Debt

$ 1,250,000

Long-term Debt, Maturity Date

^[2]

Jan. 30, 2031

Boston Properties Limited Partnership | Senior Notes | 2.671% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.55%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.671%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Apr. 01, 2032

Boston Properties Limited Partnership | Senior Notes | 2.524% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

2.45%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

2.524%

Debt

$ 850,000

Long-term Debt, Maturity Date

^[2]

Oct. 01, 2033

Boston Properties Limited Partnership | Senior Notes | 6.619% unsecured senior notes

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

6.50%

Debt Instrument, Interest Rate, Effective Percentage

^[1]

6.619%

Debt

$ 750,000

Long-term Debt, Maturity Date

^[2]

Jan. 15, 2034

Boston Properties Limited Partnership | Senior Notes | Five point Eight Four Two Percent

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Stated Percentage

5.75%

Debt Instrument, Interest Rate, Effective Percentage

5.842%

Debt

$ 850,000

Long-term Debt, Maturity Date

Jan. 15, 2035

[1]	Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.
[2]	No principal amounts are due prior to maturity.

Debt (Tables)

9 Months Ended

Sep. 30, 2024

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The following summarizes the unsecured senior notes outstanding as of September 30, 2024 (dollars in thousands):


	Coupon/Stated Rate		Effective Rate(1)		Principal Amount		Maturity Date(2)
7 Year Unsecured Senior Notes	3.200	%	3.350	%	$	850,000	January 15, 2025
10 Year Unsecured Senior Notes	3.650	%	3.766	%	1,000,000		February 1, 2026
10 Year Unsecured Senior Notes	2.750	%	3.495	%	1,000,000		October 1, 2026
5 Year Unsecured Senior Notes	6.750	%	6.924	%	750,000		December 1, 2027
10 Year Unsecured Senior Notes	4.500	%	4.628	%	1,000,000		December 1, 2028
10 Year Unsecured Senior Notes	3.400	%	3.505	%	850,000		June 21, 2029
10.5 Year Unsecured Senior Notes	2.900	%	2.984	%	700,000		March 15, 2030
10.75 Year Unsecured Senior Notes	3.250	%	3.343	%	1,250,000		January 30, 2031
11 Year Unsecured Senior Notes	2.550	%	2.671	%	850,000		April 1, 2032
12 Year Unsecured Senior Notes	2.450	%	2.524	%	850,000		October 1, 2033
10.7 Year Unsecured Senior Notes	6.500	%	6.619	%	750,000		January 15, 2034
10 Year Unsecured Senior Notes	5.750	%	5.842	%	850,000		January 15, 2035
Total principal					10,700,000
Less:
Net unamortized discount					11,580
Deferred financing costs, net					46,387
Total					$	10,642,033

_______________

(1)Yield on issuance date including the effects of discounts on the notes, settlements of interest rate contracts and the amortization of financing costs.

(2)No principal amounts are due prior to maturity.

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-7

+ Details

Real Estate (Tables)

9 Months Ended

Sep. 30, 2024

Real Estate Properties [Line Items]

Schedule of Real Estate Properties

BXP

Real estate consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Land	$	5,318,724	$	5,251,224
Right of use assets - finance leases (1)	372,896		401,680
Right of use assets - operating leases (1)	339,804		324,298
Land held for future development (2)	690,774		697,061
Buildings and improvements	16,898,821		16,607,756
Tenant improvements	3,782,391		3,592,172
Furniture, fixtures and equipment	54,992		53,716
Construction in progress	812,122		547,280
Total	28,270,524		27,475,187
Less: Accumulated depreciation	(7,369,545)		(6,881,728)
	$	20,900,979	$	20,593,459

_______________

(1)See Note 4.

(2)Includes pre-development costs.

901 New York Avenue

Real Estate Properties [Line Items]

Asset Acquisition

The following table summarizes the allocation of the fair value of the net assets the Company received at the date of acquisition for 901 New York Avenue (in thousands):


Land and site improvements	$	65,808
Building and improvements	56,882
Tenant improvements	16,088
In-place lease intangibles	72,621
Above-market lease intangibles	2,757
Below-market lease intangibles	(2,515)
Mortgage note payable adjustment	8,374
Net assets acquired	$	220,015

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The following table summarizes the estimated annual amortization of the acquired in-place lease intangibles, and the acquired above- and below-market lease intangibles for 901 New York Avenue from January 8, 2024 through the remainder of 2024 and each of the next five succeeding fiscal years (in thousands):


	Acquired In-Place Lease Intangibles		Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
Period from January 8, 2024 through December 31, 2024	$	10,364	$	607	$	252
2025	9,030		454		257
2026	6,494		238		257
2027	6,265		201		257
2028	6,069		186		257
2029	6,076		186		251

Schedule of Acquired Finite-Lived Intangible Assets by Major Class

The following table summarizes the weighted-average useful life of the acquired in-place lease intangibles and the acquired above- and below-market lease intangibles for 901 New York Avenue as of the acquisition date (in years):


	Acquired In-Place Lease Intangibles	Acquired Above-Market Lease Intangibles	Acquired Below-Market Lease Intangibles
Weighted-average useful life	6.7	4.0	9.8

Boston Properties Limited Partnership

Real Estate Properties [Line Items]

Schedule of Real Estate Properties

BPLP

Real estate consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Land	$	5,224,015	$	5,156,515
Right of use assets - finance leases (1)	372,896		401,680
Right of use assets - operating leases (1)	339,804		324,298
Land held for future development (2)	690,774		697,061
Buildings and improvements	16,627,265		16,336,200
Tenant improvements	3,782,391		3,592,172
Furniture, fixtures and equipment	54,992		53,716
Construction in progress	812,122		547,280
Total	27,904,259		27,108,922
Less: Accumulated depreciation	(7,241,074)		(6,758,361)
	$	20,663,185	$	20,350,561

_______________

(1)See Note 4.

(2)Includes pre-development costs.

Organization	9 Months Ended
Organization	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization BXP is a fully integrated, self-administered and self-managed REIT. BXP is the sole general partner of BPLP, its operating partnership, and at September 30, 2024, owned an approximate 89.6% (89.4% at December 31, 2023) general and limited partnership interest in BPLP. Unless stated otherwise or the context requires, the “Company” refers to BXP and its subsidiaries, including BPLP and its consolidated subsidiaries. Partnership interests in BPLP include: •common units of partnership interest (also referred to as “OP Units”) and •long term incentive units of partnership interest (also referred to as “LTIP Units”) Unless specifically noted otherwise, all references to OP Units exclude units held by BXP. A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP is obligated to redeem the OP Unit for cash equal to the value of a share of common stock of BXP (“Common Stock”). In lieu of such cash redemption, BXP may elect to acquire the OP Unit for one share of Common Stock. Because the number of shares of Common Stock outstanding at all times equals the number of OP Units that BXP owns, one share of Common Stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of Common Stock. The Company uses LTIP Units as a form of time-based, restricted equity compensation and as a form of performance-based equity compensation for employees, and has previously granted LTIP Units in the form of (1) 2012 outperformance plan awards (“2012 OPP Units”) and (2) 2013 - 2024 multi-year, long-term incentive program awards (also referred to as “MYLTIP Units”), each of which, upon the satisfaction of certain performance-based and time-based vesting conditions, is convertible into one OP Unit. The three-year measurement periods for the 2012 OPP Units and the 2013 - 2021 MYLTIP Units have ended and BXP’s total stockholder return (“TSR”) was sufficient for employees to earn and therefore become eligible to vest in a portion of the awards. Unless and until they are earned, the rights, preferences and privileges of the 2022 - 2024 MYLTIP Units differ from other LTIP Units granted to employees (including the 2012 OPP Units and the 2013 - 2021 MYLTIP Units, which have been earned). Therefore, unless specifically noted otherwise, all references to LTIP Units exclude the 2022 - 2024 MYLTIP Units. LTIP Units (including the earned 2012 OPP Units and the earned 2013 - 2021 MYLTIP Units), whether vested or not, receive the same quarterly per unit distributions as OP Units, which equal per share dividends on Common Stock (See Notes 9 and 13). Properties At September 30, 2024, the Company owned or had joint venture interests in a portfolio of 184 commercial real estate properties (the “Properties”) aggregating approximately 53.0 million net rentable square feet of primarily office properties, including nine properties under construction/redevelopment totaling approximately 2.7 million net rentable square feet. At September 30, 2024, the Properties consisted of: •162 office and life sciences properties (including six properties under construction/redevelopment); •14 retail properties (including one property under construction); •seven residential properties (including two properties under construction); and •one hotel.

Real Estate (Narrative) (Details)
$ in Thousands

3 Months Ended

9 Months Ended

Mar. 31, 2024

USD ($)

Jan. 08, 2024

USD ($)

ft²

Sep. 30, 2024

USD ($)

ft²

Real_Estate_Properties

Sep. 30, 2023

USD ($)

Sep. 30, 2024

USD ($)

ft²

Real_Estate_Properties

Sep. 30, 2024

USD ($)

ft²

Real_Estate_Properties

Sep. 30, 2023

USD ($)

Sep. 26, 2024

ft²

Jul. 22, 2024

USD ($)

Jul. 17, 2024

ft²

May 07, 2024

USD ($)

ft²

Apr. 05, 2024

ft²

Feb. 12, 2024

ft²

apartments

Jan. 07, 2024

USD ($)

Dec. 31, 2023

USD ($)

Real Estate Properties [Line Items]

Total revenue

$ 859,227

$ 824,283

$ 2,549,148

$ 2,444,636

Net Income (Loss)

83,628

(111,826)

243,126

70,290

Carying value of the Company's investment in unconsolidated joint ventures

1,421,886

$ 1,421,886

1,421,886

$ 1,377,319

Impairment loss

$ 0

$ 13,615

$ 0

901 New York Avenue LLC [Member]

Real Estate Properties [Line Items]

Ownership Percentage

^[1]

25.00%

Construction in Progress

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

2,700,000

Number of real estate properties | Real_Estate_Properties

901 New York Avenue

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

524,000

Payments to Acquire Investments

$ 10,000

Net Working Capital, Including Cash Acquired from Acquisition

7,100

Gain on sale / consolidation

21,800

Total revenue

$ 24,700

Net Income (Loss)

$ (6,900)

Asset Acquisition, Consideration Transferred

20,000

901 New York Avenue | Unconsolidated Properties

Real Estate Properties [Line Items]

Gain on sale / consolidation

21,800

901 New York Avenue | 901 New York Avenue LLC [Member]

Real Estate Properties [Line Items]

Carying value of the Company's investment in unconsolidated joint ventures

$ (11,800)

Investments in Affiliates, Subsidiaries, Associates, and Joint Ventures, Fair Value Disclosure

10,000

901 New York Avenue | 901 New York Avenue LLC [Member] | Unconsolidated Properties

Real Estate Properties [Line Items]

Ownership Percentage

50.00%

901 New York Avenue | Mortgages [Member]

Real Estate Properties [Line Items]

Debt

207,100

Assumption of mortgage notes payable

$ 207,100

901 New York Avenue | Joint Venture Partner [Member] | 901 New York Avenue LLC [Member]

Real Estate Properties [Line Items]

Ownership Percentage

50.00%

901 New York Avenue | Joint Venture Partner [Member] | 901 New York Avenue LLC [Member] | Unconsolidated Properties

Real Estate Properties [Line Items]

Ownership Percentage

50.00%

121 Broadway | Construction in Progress | Residential Properties [Member]

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

492,000

Number of Units in Real Estate Property | apartments

439

760 Boylston Street

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

118,000

Reston Next Office Phase II

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

90,000

180 CityPoint [Member]

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

329,000

Shady Grove Innovation District [Member]

Real Estate Properties [Line Items]

Net Rentable Area (in sf) | ft²

143,000

Impairment loss

$ 13,600

Number of real estate properties

Contractual Sales Price

$ 24,700

$ 24,800

[1]

At December 31, 2023, the Company’s economic ownership was approximately 50%. On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest for a gross purchase price of

$10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.

Derivative Instruments and Hedging Activities (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Gain (Loss) from interest rate contracts	$ 0	$ 0	$ 0	$ 0
Interest Rate Cap
Derivative [Line Items]
Derivative, Notional Amount					$ 600,000
Derivative, Number of Instruments Held					2

Earnings Per Share / Common Unit (Tables)

9 Months Ended

Sep. 30, 2024

Entity Information [Line Items]

Computation Of Basic And Diluted Earnings Per Share / Unit


	Three months ended September 30, 2024
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc.	$	83,628	157,725	$	0.53


Effect of Dilutive Securities:
Stock Based Compensation	—		488	—
Diluted Earnings:
Net income attributable to BXP, Inc.	$	83,628	158,213	$	0.53

	Three months ended September 30, 2023
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income (loss) attributable to BXP, Inc.	$	(111,826)	156,880	$	(0.71)


Effect of Dilutive Securities:
Stock Based Compensation	—		—	—
Diluted Earnings:
Net income (loss) attributable to BXP, Inc.	$	(111,826)	156,880	$	(0.71)


	Nine months ended September 30, 2024
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc. common shareholders	$	243,126	157,250	$	1.55


Effect of Dilutive Securities:
Stock Based Compensation	—		297	(0.01)
Diluted Earnings:
Net income attributable to BXP, Inc. common shareholders	$	243,126	157,547	$	1.54

	Nine months ended September 30, 2023
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc. common shareholders	$	70,290	156,837	$	0.45


Effect of Dilutive Securities:
Stock Based Compensation	—		340	—
Diluted Earnings:
Net income attributable to BXP, Inc. common shareholders	$	70,290	157,177	$	0.45

Boston Properties Limited Partnership

Entity Information [Line Items]

Computation Of Basic And Diluted Earnings Per Share / Unit


	Three months ended September 30, 2024
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership	$	94,919	175,446	$	0.54


Effect of Dilutive Securities:
Stock Based Compensation	—		488	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership	$	94,919	175,934	$	0.54

	Three months ended September 30, 2023
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income (loss) attributable to Boston Properties Limited Partnership	$	(122,696)	174,882	$	(0.70)


Effect of Dilutive Securities:
Stock Based Compensation	—		—	—
Diluted Earnings:
Net income (loss) attributable to Boston Properties Limited Partnership	$	(122,696)	174,882	$	(0.70)


	Nine months ended September 30, 2024
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	276,826	175,369	$	1.58


Effect of Dilutive Securities:
Stock Based Compensation	—		297	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	276,826	175,666	$	1.58

	Nine months ended September 30, 2023
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	84,232	174,765	$	0.48


Effect of Dilutive Securities:
Stock Based Compensation	—		340	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	84,232	175,105	$	0.48

Real Estate Amortization of Finite Lived Intangible Assets by Major Class (Details) - 901 New York Avenue $ in Thousands	Jan. 08, 2024 USD ($)
In-Place Lease Intangibles
Acquired Finite-Lived Intangible Assets [Line Items]
Period from acquisition through December 31, 2024	$ 10,364
2025	9,030
2026	6,494
2027	6,265
2028	6,069
2029	6,076
Above Market Lease Intangibles [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Period from acquisition through December 31, 2024	607
2025	454
2026	238
2027	201
2028	186
2029	186
Below Market Lease [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Period from acquisition through December 31, 2024	252
2025	257
2026	257
2027	257
2028	257
2029	$ 251

Leases (Tables)

9 Months Ended

Sep. 30, 2024

Lessor, Lease, Description [Line Items]

Operating Lease, Lease Income [Table Text Block]

The following table summarizes the components of lease revenue recognized under the Company’s operating and sales-type leases for the three and nine months ended September 30, 2024 and 2023 and included within the Company's Consolidated Statements of Operations (in thousands):


	Three months ended September 30,				Nine months ended September 30,
Lease Revenue	2024		2023		2024		2023
Fixed contractual payments	$	646,979	$	626,738	$	1,947,599	$	1,877,573
Variable lease payments	152,242		140,210		430,279		407,528
Sales-type lease revenue	250		233		738		688
	$	799,471	$	767,181	$	2,378,616	$	2,285,789

Sales-type Lease, Lease Income


	Three months ended September 30,				Nine months ended September 30,
Lease Revenue	2024		2023		2024		2023
Fixed contractual payments	$	646,979	$	626,738	$	1,947,599	$	1,877,573
Variable lease payments	152,242		140,210		430,279		407,528
Sales-type lease revenue	250		233		738		688
	$	799,471	$	767,181	$	2,378,616	$	2,285,789

171 Dartmouth Street air rights [Member]

Lessee, Lease, Description [Line Items]

Lessee, Operating Lease, Liability, Maturity

The following table provides a maturity analysis for the air rights operating lease as of March 28, 2024 (in thousands):


	Operating
Period from March 28, 2024 through December 31, 2024	$	—
2025	750
2026	750
2027	750
2028	25,826
2029	500
Thereafter	2,000
Total lease payments	30,576
Less: Interest portion	7,391
Present value of lease payments	$	23,185

Leases

9 Months Ended

Sep. 30, 2024

Leases [Abstract]

Lessor, Operating Leases [Text Block]

4. Leases

Lessor


	Three months ended September 30,				Nine months ended September 30,
Lease Revenue	2024		2023		2024		2023
Fixed contractual payments	$	646,979	$	626,738	$	1,947,599	$	1,877,573
Variable lease payments	152,242		140,210		430,279		407,528
Sales-type lease revenue	250		233		738		688
	$	799,471	$	767,181	$	2,378,616	$	2,285,789

Lessee, Operating Leases

Lessee

On March 28, 2024, the Company entered into a 90-year air rights lease with the Massachusetts Department of Transportation for an approximately 61,000 square foot site at the parking garage located at 100 Clarendon Street and the concourse level of the Massachusetts Bay Transportation Authority’s Back Bay Station (the “Station”). The lease requires annual base rental payments of $250,000 until the commencement of construction, as defined in the lease. If the Company commences construction of a project on the site on or before August 1, 2028, then a final fixed rental payment is due in accordance with the lease at that time. After August 1, 2028, if the Company commences construction of a project on the site, then a final rental payment based on the then current fair market value will be due at that time. In addition, the lease requires annual payments of $500,000 through 2033 to fund maintenance and improvements to the Station. The Company has assumed that it will begin construction on the site on or before August 1, 2028. The incremental borrowing rate for this lease is 6.57% per annum. The net present value of the ground lease payments is approximately $23.2 million. The Company classifies this lease as an operating lease. As a result, the Company recorded a Right of Use Assets – Operating Leases and Lease Liabilities – Operating Leases of approximately $23.9 million and $23.2 million, respectively, on its Consolidated Balance Sheets at March 31, 2024. The ground lease had operating lease costs of approximately $87,000 for the three months ended September 30, 2024 and approximately $0.2 million for the period from March 28, 2024 through September 30, 2024.

The following table provides a maturity analysis for the air rights operating lease as of March 28, 2024 (in thousands):


	Operating
Period from March 28, 2024 through December 31, 2024	$	—
2025	750
2026	750
2027	750
2028	25,826
2029	500
Thereafter	2,000
Total lease payments	30,576
Less: Interest portion	7,391
Present value of lease payments	$	23,185

Lessee, Finance Leases

The Company has a ground lease for the land underlying its residential property, The Skylyne, in Oakland, California. The Skylyne is a residential property consisting of 402 residential units and supporting retail space totaling approximately 331,000 net rentable square feet. The ground lease has approximately 92-years remaining (including extension options) and provides the Company with the right to purchase the land subject to certain conditions. When the lease was executed in 2017, the purchase option was considered a bargain purchase option

and, as a result, the Company classified it as a finance lease and the Company assumed the lessor would exercise its right to require the Company to purchase the land in May 2024 for approximately $38.7 million. In May 2024 and as of the date of this report, the lessor has not exercised this option and the Company reassessed the accounting for the ground lease and determined that the purchase option continues to be considered a bargain purchase option and the ground lease will continue to be accounted for as a finance lease. The lease requires monthly base rental payments of a nominal amount until the purchase occurs, which the Company now estimates will be in 2030. As a result of the reassessment, the lease liability was remeasured and reduced to approximately $0.1 million. In conjunction with the reduction in the lease liability, the right of use asset was reduced to $0 and the difference between the lease liability and right of use asset of approximately $9.5 million was recorded as a decrease to interest expense for the nine months ended September 30, 2024. There can be no assurance that this transaction will be consummated on the terms currently contemplated or at all.

Derivative Instruments and Hedging Activities (Tables)

9 Months Ended

Sep. 30, 2024

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Interest Rate Derivatives

BPLP’s and SMBP LLC’s derivative contracts consisted of the following at September 30, 2024 (dollars in thousands):


Derivative Instrument	Aggregate Notional Amount				Strike Rate Range					Balance Sheet Location
			Effective Date	Maturity Date	Low			High			Fair Value
BPLP:
Interest Rate Swaps	$	600,000	December 15, 2023	October 26, 2028	3.790	%	—	3.798	%	Other liabilities	$	(12,600)
Interest Rate Swaps	100,000		September 27, 2024	April 1, 2025	2.688	%	—	2.688	%	Prepaid expenses and other assets	799
	700,000										(11,801)
SMBP LLC (1)
Interest Rate Swaps	200,000		December 14, 2023	April 1, 2025	2.661	%	—	2.688	%	Prepaid expenses and other assets	1,610
	$	900,000									$	(10,191)

_______________

(1)A consolidated subsidiary of the Company that is the borrower under the mortgage loan collateralized by its Santa Monica Business Park property.

Derivative Instruments, Gain (Loss)


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Amount of gain (loss) related to the effective portion recognized in other comprehensive income (1)	$	(32,263)	$	5,459	$	(14,976)	$	13,886
Amount of gain (loss) related to the effective portion subsequently reclassified to earnings (2)	$	3,077	$	1,677	$	9,518	$	5,026
Amount of gain (loss) related do the ineffective portion and amount excluded from effectiveness testing	$	—	$	—	$	—	$	—

_______________

(1)Includes the Company’s share of gain (loss) related to the effective portion of derivatives outstanding at its unconsolidated joint venture properties.

(2)Includes amounts from previous interest rate programs.

Investments in Unconsolidated Joint Ventures (Investments in Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands

9 Months Ended

12 Months Ended

Jan. 08, 2024

Sep. 30, 2024

Dec. 31, 2023

Schedule of Equity Method Investments [Line Items]

Other Liabilities

$ (407,441)

$ (445,947)

Investments in unconsolidated joint ventures

1,421,886

1,377,319

Investments In Affiliates Subsidiaries Associates And Joint Ventures net

^[1]

1,391,149

1,337,416

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Other Liabilities

$ (30,700)

(39,900)

Square 407 Limited Partnership [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Market Square North

Ownership Percentage

50.00%

Other Liabilities

^[1]

$ (12,042)

$ (5,996)

901 New York Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

901 New York Avenue

Ownership Percentage

^[2]

25.00%

Other Liabilities

^[1]

$ (11,764)

901 New York Avenue LLC (economic ownership) [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Payments to Acquire Real Estate and Real Estate Joint Ventures

$ 10,000

901 New York Avenue LLC (economic ownership) [Member] | Joint Venture Partner [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

WP Project Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Wisconsin Place Land and Infrastructure

Ownership Percentage

^[3]

33.33%

Investments in unconsolidated joint ventures

^[1]

$ 29,969

$ 30,375

500 North Capitol Venture LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

500 North Capitol Street, NW

Ownership Percentage

30.00%

Other Liabilities

^[1]

$ (11,630)

(10,253)

501 K Street LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

1001 6th Street

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 45,955

44,774

Podium Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

The Hub on Causeway - Podium

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 42,916

45,201

Residential Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Hub50House

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 38,116

40,235

Hotel Tower Developer LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

The Hub on Causeway - Hotel Air Rights

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 14,076

13,494

Office Tower Developer LLC

Schedule of Equity Method Investments [Line Items]

Properties

100 Causeway Street

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 56,055

57,660

1265 Main Office JV LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

1265 Main Street

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 3,515

3,585

BNY Tower Holdings LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Dock 72

Ownership Percentage

^[4]

50.00%

Other Liabilities

^[1]

$ (7,065)

(11,890)

CA-Colorado Center LLC[Member]

Schedule of Equity Method Investments [Line Items]

Properties

Colorado Center

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 234,972

237,815

7750 Wisconsin Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

7750 Wisconsin Avenue

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 48,814

50,064

BP-M 3HB Venture LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

3 Hudson Boulevard

Ownership Percentage

25.00%

Investments in unconsolidated joint ventures

^[1]

$ 113,288

115,103

Platform 16 Holdings LP [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Platform 16

Ownership Percentage

55.00%

Investments in unconsolidated joint ventures

^[1]

$ 55,381

45,564

Gateway Portfolio Holdings LLC [Member]

Schedule of Equity Method Investments [Line Items]

Properties

Gateway Commons

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 393,679

376,834

Rosecrans-Sepulveda Partners 4, LLC

Schedule of Equity Method Investments [Line Items]

Properties

Beach Cities Media Campus

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 27,051

27,034

Safeco Plaza REIT LLC

Schedule of Equity Method Investments [Line Items]

Properties

Safeco Plaza

Ownership Percentage

^[5]

33.67%

Investments in unconsolidated joint ventures

^[1]

$ 47,510

44,734

Safeco Plaza REIT LLC | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

33.00%

360 PAS Holdco LLC

Schedule of Equity Method Investments [Line Items]

Properties

360 Park Avenue South

Ownership Percentage

^[6]

71.11%

Investments in unconsolidated joint ventures

^[1]

$ 69,538

42,988

360 PAS Holdco LLC | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

35.79%

PR II BXP Reston Gateway LLC

Schedule of Equity Method Investments [Line Items]

Properties

Skymark - Reston Next Residential

Ownership Percentage

20.00%

Investments in unconsolidated joint ventures

^[1]

$ 15,359

15,184

751 Gateway Holdings LLC

Schedule of Equity Method Investments [Line Items]

Properties

751 Gateway

Ownership Percentage

49.00%

Investments in unconsolidated joint ventures

^[1]

$ 98,882

93,411

200 Fifth Avenue JV LLC

Schedule of Equity Method Investments [Line Items]

Properties

200 Fifth Avenue

Ownership Percentage

26.69%

Investments in unconsolidated joint ventures

^[1]

$ 68,563

75,718

ABXP Worldgate Investments LLC

Schedule of Equity Method Investments [Line Items]

Properties

13100 and 13150 Worldgate Drive

Ownership Percentage

50.00%

Investments in unconsolidated joint ventures

^[1]

$ 18,247

$ 17,546

Entity Owning Land And Infrastructure Of Project [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

33.33%

Safeco Partner Entity One [Member] | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

Safeco Partner Entity Two | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

360 Park Avenue South Partners Entity | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

1.00%

360 PAS Holdco LLC (indirect ownership) | Company's Share [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

35.02%

[1]	Investments with deficit balances aggregating approximately $30.7 million and $39.9 million at September 30, 2024 and December 31, 2023, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.
[2]	At December 31, 2023, the Company’s economic ownership was approximately 50%. On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest for a gross purchase price of $10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.
[3]	The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project.
[4]	This property includes net equity balances from the amenity joint venture.
[5]	The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.
[6]	The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 35.02% indirect ownership in the joint venture, and (3) an additional 1% interest in the entity through which the partner owns its interest in the joint venture.

Derivative Instruments and Hedging Activities (Details) - Interest Rate Swap - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 27, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative, Notional Amount	$ 900,000
Cash Flow Hedges Derivative Instruments at Fair Value, Net	$ (10,191)		$ 1,976
325 Main Street, 355 Main Street, 90 Broadway and Kendall Center Green Garage Properties [Member]
Derivative [Line Items]
Derivative, Swap Type	Interest Rate Swaps
Derivative, Notional Amount	$ 600,000
Derivative, Maturity Date	Oct. 26, 2028
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	$ (12,600)
325 Main Street, 355 Main Street, 90 Broadway and Kendall Center Green Garage Properties and 2024 Unsecured Term Loan
Derivative [Line Items]
Derivative, Notional Amount	700,000
Cash Flow Hedges Derivative Instruments at Fair Value, Net	$ (11,801)
Santa Monica Business Park [Member]
Derivative [Line Items]
Derivative, Swap Type	Interest Rate Swaps
Derivative, Notional Amount	$ 200,000
Derivative, Maturity Date	Apr. 01, 2025
Fair Value Hedge Assets	$ 1,610
2024 Unsecured Term Loan
Derivative [Line Items]
Derivative, Swap Type	Interest Rate Swaps
Derivative, Notional Amount	$ 100,000
Derivative, Maturity Date	Apr. 01, 2025
Derivative, Fixed Interest Rate		2.688%
Fair Value Hedge Assets	$ 799
Minimum [Member] \| 325 Main Street, 355 Main Street, 90 Broadway and Kendall Center Green Garage Properties [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	3.79%
Minimum [Member] \| Santa Monica Business Park [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.661%
Minimum [Member] \| 2024 Unsecured Term Loan
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.688%
Maximum [Member] \| 325 Main Street, 355 Main Street, 90 Broadway and Kendall Center Green Garage Properties [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	3.798%
Maximum [Member] \| Santa Monica Business Park [Member]
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.688%
Maximum [Member] \| 2024 Unsecured Term Loan
Derivative [Line Items]
Derivative, Fixed Interest Rate	2.688%

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events On October 5, 2024, the Company fully placed in-service 103 CityPoint, an approximately 113,000 net rentable square foot laboratory/life sciences project located in Waltham, Massachusetts. On October 8, 2024, the Company modified the mortgage loan collateralized by its Santa Monica Business Park properties located in Santa Monica, California. The mortgage loan had an outstanding principal balance of $200.0 million, bore interest at a variable rate equal to Daily Simple SOFR + 1.38% per annum and was scheduled to mature on July 19, 2025 (See Note 6). The modified loan is scheduled to mature on October 8, 2028 and continues to bear interest at a variable rate equal to Daily Simple SOFR + 1.38% per annum until July 19, 2025. Beginning July 19, 2025, the mortgage loan will bear interest at Daily Simple SOFR + 1.60% per annum through the maturity date. The entire principal is subject to interest rate swap contracts to fix Daily Simple SOFR at a weighted-average fixed interest rate of approximately 2.675% per annum through April 1, 2025 (See Note 7). The mortgage loan requires monthly interest-only payments during the term of the loan, with the entire principal due at maturity. Santa Monica Business Park is an office park consisting of 21 buildings totaling approximately 1.2 million net rentable square feet. On October 31, 2024, the Company completed and fully placed in-service 300 Binney Street, a laboratory/life sciences redevelopment project with approximately 236,000 net rentable square feet located in Cambridge, Massachusetts. The property is fully leased to a life sciences tenant.

Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

$ 27,557,824

$ 26,749,209

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

372,896

401,680

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

^[1]

339,804

324,298

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(7,369,545)

(6,881,728)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

1,420,475

1,531,477

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

51,009

81,090

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

99,706

122,407

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

1,438,492

1,355,212

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

794,571

760,421

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

132,078

64,230

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

4,275,155

4,166,379

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

373,260

417,961

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

389,444

350,391

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

444,288

458,329

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

$ 407,441

$ 445,947

Reedemable deferred stock units, units

132,930

119,471

Limited Partners' Capital Account, Units Outstanding (in units)

156,217,471

General Partners' Capital Account, Units Outstanding (in units)

1,762,427

Excess stock, par value

$ 0.01

Excess stock, shares authorized

150,000,000

Excess stock, shares outstanding

Excess stock, shares issued

Preferred stock, par value

$ 0.01

Preferred stock, shares authorized

50,000,000

Preferred stock / units, shares / units issued (in shares / units)

Preferred stock / units, shares / units outstanding (in shares / units)

Common Stock, Par or Stated Value Per Share

$ 0.01

Common stock, shares authorized

250,000,000

Common stock, shares issued

158,058,798

157,019,766

Common Stock, Shares, Outstanding

157,979,898

156,940,866

Treasury common stock at cost, shares

78,900

Boston Properties Limited Partnership

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

$ 27,191,559

$ 26,382,944

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

372,896

401,680

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

^[1]

339,804

324,298

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(7,241,074)

(6,758,361)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

1,420,475

1,531,477

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

51,009

81,090

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

99,706

122,407

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

1,438,492

1,355,212

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

794,571

760,421

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

132,078

64,230

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

4,275,155

4,166,379

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

373,260

417,961

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

389,444

350,391

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

444,288

458,329

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

$ 407,441

$ 445,947

Reedemable deferred stock units, units

132,930

119,471

Limited Partners' Capital Account, Units Outstanding (in units)

156,217,471

155,185,716

General Partners' Capital Account, Units Outstanding (in units)

1,762,427

1,755,150

NonControlling Interest Redeemable Partnership Units Common Units Shares Outstanding

15,926,014

16,508,277

NonControlling Interest Redeemable Partnership Units Common Units Long Term Incentive Units At Redemption Value Shares Outstanding

2,336,797

2,065,861

Variable Interest Entity, Primary Beneficiary [Member]

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

$ 7,646,435

$ 7,054,075

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

21,000

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

145,052

158,885

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(1,601,919)

(1,501,483)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

322,604

245,317

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

5,032

22,160

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

19,216

27,987

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

425,867

401,159

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

201,947

175,383

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

50,275

11,824

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

3,280,817

3,277,185

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

20,897

20,794

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

154,637

145,826

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

120,092

59,667

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

89,876

115,275

Variable Interest Entity, Primary Beneficiary [Member] | Boston Properties Limited Partnership

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

7,646,435

7,054,075

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

21,000

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

145,052

158,885

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(1,601,919)

(1,501,483)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

322,604

245,317

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

5,032

22,160

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

19,216

27,987

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

425,867

401,159

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

201,947

175,383

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

50,275

11,824

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

3,280,817

3,277,185

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

20,897

20,794

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

154,637

145,826

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

120,092

59,667

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

$ 89,876

$ 115,275

[1]	See Note 4.

Investment in Unconsolidated Joint Ventures (Narrative) (Details)
$ in Thousands

3 Months Ended

9 Months Ended

Jul. 18, 2024

ft²

Jul. 17, 2024

USD ($)

Jun. 07, 2024

Feb. 09, 2024

USD ($)

ft²

Feb. 06, 2024

USD ($)

Jan. 08, 2024

USD ($)

ft²

Sep. 30, 2024

USD ($)

ft²

Sep. 30, 2023

USD ($)

Sep. 30, 2024

USD ($)

ft²

Sep. 30, 2023

USD ($)

Aug. 07, 2024

ft²

Jul. 12, 2024

ft²

apartments

May 08, 2024

Jan. 07, 2024

Jan. 02, 2024

ft²

Dec. 31, 2023

Construction in Progress

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

2,700,000

Gateway Commons Complex [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

901 New York Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[1]

25.00%

3 Hudson Boulevard [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

25.00%

7750 Wisconsin Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

PR II BXP Reston Gateway LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

20.00%

Office Tower Developer LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

360 PAS Holdco LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

^[2]

71.11%

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Gain on sale / consolidation

$ 0

$ 21,696

$ 0

Unconsolidated Properties | Gateway Commons Complex [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Unconsolidated Properties | 651 Gateway | Office and Life Sciences Building [Member]

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

327,000

901 New York Avenue

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

524,000

Payments to Acquire Investments

$ 10,000

Gain on sale / consolidation

21,800

901 New York Avenue | Mortgages [Member]

Schedule of Equity Method Investments [Line Items]

Debt

$ 207,100

Debt Instrument, Maturity Date

Jan. 05, 2025

901 New York Avenue | 901 New York Avenue LLC [Member] | Joint Venture Partner [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

901 New York Avenue | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Gain on sale / consolidation

$ 21,800

901 New York Avenue | Unconsolidated Properties | 901 New York Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

901 New York Avenue | Unconsolidated Properties | 901 New York Avenue LLC [Member] | Joint Venture Partner [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

3 Hudson Boulevard [Member] | Extended Maturity

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Maturity Date

Aug. 07, 2024

May 09, 2024

Long-Term Debt, Term

60 days

30 days

3 Hudson Boulevard [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

3.61%

Debt

$ 80,000

Long Term Debt, Including Accrued Interest

$ 116,000

3 Hudson Boulevard [Member] | Unconsolidated Properties | 3 Hudson Boulevard [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

25.00%

7750 Wisconsin Avenue [Member] | Extended Maturity

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Maturity Date

Apr. 26, 2025

7750 Wisconsin Avenue [Member] | Unconsolidated Properties

Schedule of Equity Method Investments [Line Items]

Net Rentable Area (in sf) | ft²

736,000

Construction Loan

$ 252,600

Debt Instrument, Basis Spread on Variable Rate

1.35%

Long-Term Debt

$ 251,600

7750 Wisconsin Avenue [Member] | Unconsolidated Properties | 7750 Wisconsin Avenue LLC [Member]

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Skymark | Unconsolidated Properties | PR II BXP Reston Gateway LLC | Residential Building | Construction in Progress

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

20.00%

Net Rentable Area (in sf) | ft²

417,000

Number of Units in Real Estate Property | apartments

508

Low Rise Property

Schedule of Equity Method Investments [Line Items]

Number of floors

Tower Property

Schedule of Equity Method Investments [Line Items]

Number of floors

100 Causeway Street [Member] | Unconsolidated Properties | Office Tower Developer LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

50.00%

Net Rentable Area (in sf) | ft²

634,000

Debt Instrument, Basis Spread on Variable Rate

1.48%

Debt

$ 333,600

100 Causeway Street [Member] | Unconsolidated Properties | Extended Maturity | Office Tower Developer LLC

Schedule of Equity Method Investments [Line Items]

Debt Instrument, Basis Spread on Variable Rate

1.48%

Debt Instrument, Maturity Date

Sep. 05, 2025

Long-Term Debt, Term

1 year

360 Park Avenue South | Unconsolidated Properties | 360 PAS Holdco LLC

Schedule of Equity Method Investments [Line Items]

Ownership Percentage

71.11%

Net Rentable Area (in sf) | ft²

450,000

[1]	At December 31, 2023, the Company’s economic ownership was approximately 50%. On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest for a gross purchase price of $10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.
[2]	The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 35.02% indirect ownership in the joint venture, and (3) an additional 1% interest in the entity through which the partner owns its interest in the joint venture.

Consolidated Statements Of Operations - USD ($)
shares in Thousands, $ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Revenue

Lease

$ 799,471

$ 767,181

$ 2,378,616

$ 2,285,789

Total revenue

859,227

824,283

2,549,148

2,444,636

Expenses

Rental

327,897

300,192

963,480

882,536

General and administrative

33,352

31,410

127,479

131,387

Transaction costs

188

751

890

1,970

Depreciation and amortization

222,890

207,435

661,148

618,746

Total expenses

597,809

552,714

1,790,774

1,672,241

Other income (expense)

Income (loss) from unconsolidated joint ventures

(7,011)

(247,556)

6,376

(261,793)

Gains on sales of real estate

517

Interest and other income (loss)

14,430

20,715

39,747

48,999

Gains (losses) from investments in securities

2,198

(925)

4,785

2,311

Unrealized gain (loss) on non-real estate investments

(51)

548

332

Impairment loss

(13,615)

Interest expense

(163,194)

(147,812)

(474,727)

(424,492)

Net Income (loss)

108,452

(103,543)

322,005

138,269

Net (income) loss attributable to noncontrolling interests

Noncontrolling interests in property partnerships

(15,237)

(20,909)

(50,283)

(59,337)

Noncontrolling interest - common units of the Operating Partnership

(9,587)

12,626

(28,596)

(8,642)

Net income (loss) attributable to BXP, Inc.

83,628

(111,826)

243,126

70,290

Net income attributable to the Company

$ 83,628

$ (111,826)

$ 243,126

$ 70,290

Basic earnings per common share / unit attributable to the Company common shareholders / unitholders

Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)

$ 0.53

$ (0.71)

$ 1.55

$ 0.45

Weighted average number of common shares / units outstanding (in shares / units)

157,725

156,880

157,250

156,837

Diluted earnings per common share / unit attributable to the Company common shareholders / unitholders

Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)

$ 0.53

$ (0.71)

$ 1.54

$ 0.45

Weighted average number of common and common equivalent shares / units outstanding (in shares / units)

158,213

156,880

157,547

157,177

Boston Properties Limited Partnership

Revenue

Lease

$ 799,471

$ 767,181

$ 2,378,616

$ 2,285,789

Total revenue

859,227

824,283

2,549,148

2,444,636

Expenses

Rental

327,897

300,192

963,480

882,536

General and administrative

33,352

31,410

127,479

131,387

Transaction costs

188

751

890

1,970

Depreciation and amortization

221,186

205,679

656,044

613,446

Total expenses

596,105

550,958

1,785,670

1,666,941

Other income (expense)

Income (loss) from unconsolidated joint ventures

(7,011)

(247,556)

6,376

(261,793)

Gains on sales of real estate

517

Interest and other income (loss)

14,430

20,715

39,747

48,999

Gains (losses) from investments in securities

2,198

(925)

4,785

2,311

Unrealized gain (loss) on non-real estate investments

(51)

548

332

Impairment loss

(13,615)

Interest expense

(163,194)

(147,812)

(474,727)

(424,492)

Net Income (loss)

110,156

(101,787)

327,109

143,569

Net (income) loss attributable to noncontrolling interests

Noncontrolling interests in property partnerships

(15,237)

(20,909)

(50,283)

(59,337)

Net income (loss) attributable to BXP, Inc.

94,919

(122,696)

276,826

84,232

Net income attributable to the Company

$ 94,919

$ (122,696)

$ 276,826

$ 84,232

Basic earnings per common share / unit attributable to the Company common shareholders / unitholders

Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)

$ 0.54

$ (0.70)

$ 1.58

$ 0.48

Weighted average number of common shares / units outstanding (in shares / units)

175,446

174,882

175,369

174,765

Diluted earnings per common share / unit attributable to the Company common shareholders / unitholders

Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)

$ 0.54

$ (0.70)

$ 1.58

$ 0.48

Weighted average number of common and common equivalent shares / units outstanding (in shares / units)

175,934

174,882

175,666

175,105

Parking and Other [Member]

Revenue

Other revenue

$ 34,255

$ 30,428

$ 101,086

$ 81,421

Parking and Other [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

34,255

30,428

101,086

81,421

Hotel [Member]

Revenue

Other revenue

15,082

^[1]

13,484

^[1]

38,080

^[2]

35,554

^[2]

Expenses

Operating expense

9,833

9,020

25,687

23,852

Hotel [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

15,082

13,484

38,080

35,554

Expenses

Operating expense

9,833

9,020

25,687

23,852

Management Service [Member]

Revenue

Other revenue

6,770

9,284

19,276

28,122

Management Service [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

6,770

9,284

19,276

28,122

Real Estate, Other [Member]

Revenue

Other revenue

3,649

3,906

12,090

13,750

Expenses

Operating expense

3,649

3,906

12,090

13,750

Real Estate, Other [Member] | Boston Properties Limited Partnership

Revenue

Other revenue

3,649

3,906

12,090

13,750

Expenses

Operating expense

$ 3,649

$ 3,906

$ 12,090

$ 13,750

[1]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.
[2]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Lease Liability Maturity Schedule 171 Dartmouth Street (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 28, 2024	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating Lease, Liability	$ 389,444		$ 350,391
171 Dartmouth Street air rights [Member]
Lessee, Lease, Description [Line Items]
Period from March 28, 2024 - December 31, 2024		$ 0
2025		750
2026		750
2027		750
2028		25,826
2029		500
Thereafter		2,000
Total lease payments		30,576
Less: Interest Portion		7,391
Operating Lease, Liability		$ 23,185

Noncontrolling Interests (Tables)

9 Months Ended

Sep. 30, 2024

Noncontrolling Interest [Line Items]

Schedule of Noncontrolling Interest [Table Text Block]

Noncontrolling interests relate to the interests in BPLP not owned by BXP and interests in consolidated property partnerships not wholly-owned by the Company. As of September 30, 2024, the noncontrolling interests in BPLP consisted of the following:


OP Units	LTIP Units (1)	2022 MYLTIP Units	2023 MYLTIP Units	2024 MYLTIP Units
15,926,014	2,336,797	252,151	322,053	330,479

__________

(1)Includes 617,961 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2021 (i.e., 2012 OPP and 2013 - 2021 MYLTIP awards).

Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2024 and during the nine months ended September 30, 2023:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
September 30, 2024	October 31, 2024	$0.98	$0.98
June 28, 2024	July 31, 2024	$0.98	$0.98
March 28, 2024	April 30, 2024	$0.98	$0.98
December 29, 2023	January 30, 2024	$0.98	$0.98
September 29, 2023	October 31, 2023	$0.98	$0.98
June 30, 2023	July 31, 2023	$0.98	$0.98
March 31, 2023	April 28, 2023	$0.98	$0.98
December 30, 2022	January 30, 2023	$0.98	$0.98

Noncontrolling Interests [Member]

Noncontrolling Interest [Line Items]

Distribution Declared to OP, LTIP, OPP and MYLTIP Units [Table Text Block]

The following table presents BPLP’s distributions on the OP Units and LTIP Units and MYLTIP Units paid or declared in 2024 and during the nine months ended September 30, 2023:


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
September 30, 2024	October 31, 2024	$0.98	$0.098
June 28, 2024	July 31, 2024	$0.98	$0.098
March 28, 2024	April 30, 2024	$0.98	$0.098
December 29, 2023	January 30, 2024	$0.98	$0.098
September 29, 2023	October 31, 2023	$0.98	$0.098
June 30, 2023	July 31, 2023	$0.98	$0.098
March 31, 2023	April 28, 2023	$0.98	$0.098
December 30, 2022	January 30, 2023	$0.98	$0.098

Schedule of Noncontrolling Interests (Details) - Boston Properties Limited Partnership

Sep. 30, 2024

OP Units [Member]

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

15,926,014

LTIP Units [Member]

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

2,336,797

^[1]

MYLTIP 2022

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

252,151

MYLTIP 2023

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

322,053

MYLTIP 2024

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

330,479

2012 OPP and 2013-2021 MYLTIP [Member]

Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]

Noncontrolling Interest, Outstanding

617,961

[1]	Includes 617,961 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2021 (i.e., 2012 OPP and 2013 - 2021 MYLTIP awards).

Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands				3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	9			9		9
Separate Unrestricted Cash For Deferred Compensation Plan.	$ 38,900		$ 36,100	$ 38,900		$ 38,900
Impairment loss				0	$ 0	13,615	$ 0
Unsecured commercial paper	500,000		0	500,000		500,000
Gains (losses) from investments in securities				2,198	(925)	4,785	2,311
Prepaid Expense and Other Assets	$ 132,078		64,230	$ 132,078		$ 132,078
Unconsolidated Joint Ventures [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	0			0		0
Deferred Compensation, Excluding Share-Based Payments and Retirement Benefits
Summary Of Significant Accounting Policies [Line Items]
Gains (losses) from investments in securities				$ 2,200	$ (900)	$ 4,800	$ 2,300
Shady Grove Innovation District [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment loss		$ 13,600				13,600
Environmental Focused Investment Fund
Summary Of Significant Accounting Policies [Line Items]
Prepaid Expense and Other Assets	$ 6,700		$ 4,600	6,700		6,700
US Treasury Bill Securities
Summary Of Significant Accounting Policies [Line Items]
U.S. Treasury Bill, Term of Contract	3 months		3 months
3-Month United States Treasury Bills	$ 175,900		$ 302,700	$ 175,900		$ 175,900
Variable Interest Entity, Primary Beneficiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	9			9		9
Prepaid Expense and Other Assets	$ 50,275		$ 11,824	$ 50,275		$ 50,275
Commercial Real Estate Properties [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of VIEs	5			5		5

Segment Information (Schedule Of Segment Reporting By Geographic Area And Property Type) (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 821,609

^[1]

$ 785,820

^[1]

$ 2,442,675

^[2]

$ 2,331,442

^[2]

Rental Revenue: Residential

12,117

^[1]

11,789

^[1]

37,027

^[2]

35,768

^[2]

Rental Revenue Total

$ 848,808

^[1]

$ 811,093

^[1]

$ 2,517,782

^[2]

$ 2,402,764

^[2]

Rental Revenue: % of Grand Totals

100.00%

Rental Expenses: Office

$ 321,909

$ 294,454

$ 946,067

$ 865,552

Rental Expenses: Residential

5,988

5,738

17,413

16,984

Rental Expenses: Total

$ 337,730

$ 309,212

$ 989,167

$ 906,388

Rental Expenses: % Of Grand Totals

100.00%

Net Operating Income

$ 511,078

$ 501,881

$ 1,528,615

$ 1,496,376

Net Operating Income: % of Grand Totals

100.00%

Company's Share of Net Operating Income: % of Grand Totals

100.00%

Boston [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 300,613

^[1]

$ 276,153

^[1]

$ 866,431

^[2]

$ 815,568

^[2]

Rental Revenue: Residential

4,219

^[1]

4,198

^[1]

12,687

^[2]

12,371

^[2]

Rental Revenue Total

$ 319,914

^[1]

$ 293,835

^[1]

$ 917,198

^[2]

$ 863,493

^[2]

Rental Revenue: % of Grand Totals

37.69%

36.23%

36.42%

35.95%

Rental Expenses: Office

$ 107,876

$ 97,358

$ 321,955

$ 293,004

Rental Expenses: Residential

1,621

1,629

4,757

4,782

Rental Expenses: Total

$ 119,330

$ 108,007

$ 352,399

$ 321,638

Rental Expenses: % Of Grand Totals

35.34%

34.94%

35.62%

35.49%

Net Operating Income

$ 200,584

$ 185,828

$ 564,799

$ 541,855

Net Operating Income: % of Grand Totals

39.25%

37.03%

36.96%

36.22%

Company's Share of Net Operating Income: % of Grand Totals

39.89%

37.07%

37.51%

36.19%

Los Angeles [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 18,661

^[1]

$ 0

^[1]

$ 57,534

^[2]

$ 0

^[2]

Rental Revenue: Residential

^[1]

^[2]

Rental Revenue Total

$ 18,661

^[1]

$ 0

^[1]

$ 57,534

^[2]

$ 0

^[2]

Rental Revenue: % of Grand Totals

2.20%

0.00%

2.29%

0.00%

Rental Expenses: Office

$ 7,344

$ 0

$ 20,678

$ 0

Rental Expenses: Residential

Rental Expenses: Total

$ 7,344

$ 0

$ 20,678

$ 0

Rental Expenses: % Of Grand Totals

2.17%

0.00%

2.09%

0.00%

Net Operating Income

$ 11,317

$ 0

$ 36,856

$ 0

Net Operating Income: % of Grand Totals

2.21%

0.00%

2.41%

0.00%

Company's Share of Net Operating Income: % of Grand Totals

3.64%

2.55%

3.89%

2.61%

New York [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 258,295

^[1]

$ 268,680

^[1]

$ 780,909

^[2]

$ 789,851

^[2]

Rental Revenue: Residential

^[1]

^[2]

Rental Revenue Total

$ 258,295

^[1]

$ 268,680

^[1]

$ 780,909

^[2]

$ 789,851

^[2]

Rental Revenue: % of Grand Totals

30.43%

33.13%

31.02%

32.87%

Rental Expenses: Office

$ 111,419

$ 107,462

$ 327,376

$ 312,895

Rental Expenses: Residential

Rental Expenses: Total

$ 111,419

$ 107,462

$ 327,376

$ 312,895

Rental Expenses: % Of Grand Totals

32.99%

34.75%

33.10%

34.52%

Net Operating Income

$ 146,876

$ 161,218

$ 453,533

$ 476,956

Net Operating Income: % of Grand Totals

28.74%

32.12%

29.67%

31.87%

Company's Share of Net Operating Income: % of Grand Totals

23.41%

25.84%

24.21%

25.57%

San Francisco [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 128,929

^[1]

$ 135,839

^[1]

$ 393,252

^[2]

$ 408,173

^[2]

Rental Revenue: Residential

3,152

^[1]

3,214

^[1]

10,428

^[2]

10,720

^[2]

Rental Revenue Total

$ 132,081

^[1]

$ 139,053

^[1]

$ 403,680

^[2]

$ 418,893

^[2]

Rental Revenue: % of Grand Totals

15.56%

17.14%

16.03%

17.43%

Rental Expenses: Office

$ 52,410

$ 50,450

$ 148,020

$ 144,732

Rental Expenses: Residential

2,346

2,221

6,733

6,609

Rental Expenses: Total

$ 54,756

$ 52,671

$ 154,753

$ 151,341

Rental Expenses: % Of Grand Totals

16.21%

17.03%

15.64%

16.70%

Net Operating Income

$ 77,325

$ 86,382

$ 248,927

$ 267,552

Net Operating Income: % of Grand Totals

15.13%

17.21%

16.28%

17.88%

Company's Share of Net Operating Income: % of Grand Totals

16.37%

18.41%

17.65%

18.89%

Seattle

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 10,821

^[1]

$ 13,660

^[1]

$ 32,251

^[2]

$ 44,978

^[2]

Rental Revenue: Residential

^[1]

^[2]

Rental Revenue Total

$ 10,821

^[1]

$ 13,660

^[1]

$ 32,251

^[2]

$ 44,978

^[2]

Rental Revenue: % of Grand Totals

1.27%

1.68%

1.28%

1.87%

Rental Expenses: Office

$ 3,382

$ 2,971

$ 9,753

$ 9,013

Rental Expenses: Residential

Rental Expenses: Total

$ 3,382

$ 2,971

$ 9,753

$ 9,013

Rental Expenses: % Of Grand Totals

1.00%

0.96%

0.99%

Net Operating Income

$ 7,439

$ 10,689

$ 22,498

$ 35,965

Net Operating Income: % of Grand Totals

1.46%

2.13%

1.47%

2.40%

Company's Share of Net Operating Income: % of Grand Totals

1.87%

2.56%

1.89%

2.82%

Washington, DC [Member]

Segment Reporting Information [Line Items]

Rental Revenue: Office

$ 104,290

^[1]

$ 91,488

^[1]

$ 312,298

^[2]

$ 272,872

^[2]

Rental Revenue: Residential

4,746

^[1]

4,377

^[1]

13,912

^[2]

12,677

^[2]

Rental Revenue Total

$ 109,036

^[1]

$ 95,865

^[1]

$ 326,210

^[2]

$ 285,549

^[2]

Rental Revenue: % of Grand Totals

12.85%

11.82%

12.96%

11.88%

Rental Expenses: Office

$ 39,478

$ 36,213

$ 118,285

$ 105,908

Rental Expenses: Residential

2,021

1,888

5,923

5,593

Rental Expenses: Total

$ 41,499

$ 38,101

$ 124,208

$ 111,501

Rental Expenses: % Of Grand Totals

12.29%

12.32%

12.56%

12.30%

Net Operating Income

$ 67,537

$ 57,764

$ 202,002

$ 174,048

Net Operating Income: % of Grand Totals

13.21%

11.51%

13.21%

11.63%

Company's Share of Net Operating Income: % of Grand Totals

14.82%

13.57%

14.85%

13.92%

Hotel [Member]

Segment Reporting Information [Line Items]

Other revenue

$ 15,082

^[1]

$ 13,484

^[1]

$ 38,080

^[2]

$ 35,554

^[2]

Operating expense

9,833

9,020

25,687

23,852

Hotel [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Other revenue

15,082

^[1]

13,484

^[1]

38,080

^[2]

35,554

^[2]

Operating expense

9,833

9,020

25,687

23,852

Hotel [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

^[2]

Operating expense

Hotel [Member] | New York [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

^[2]

Operating expense

Hotel [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

^[2]

Operating expense

Hotel [Member] | Seattle

Segment Reporting Information [Line Items]

Other revenue

^[1]

^[2]

Operating expense

Hotel [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Other revenue

^[1]

^[2]

Operating expense

Noncontrolling interest - property partnerships [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(44,487)

(50,047)

(138,448)

(145,102)

Noncontrolling interest - property partnerships [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(10,823)

(11,786)

(32,803)

(33,946)

Noncontrolling interest - property partnerships [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

(33,664)

(38,261)

(105,645)

(111,156)

Noncontrolling interest - property partnerships [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

Noncontrolling interest - property partnerships [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

Unconsolidated Joint Ventures [Member]

Segment Reporting Information [Line Items]

Net Operating Income

31,919

39,165

98,936

122,175

Unconsolidated Joint Ventures [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

9,099

7,946

26,547

25,294

Unconsolidated Joint Ventures [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

6,835

12,508

21,118

38,501

Unconsolidated Joint Ventures [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

3,472

3,938

12,614

10,951

Unconsolidated Joint Ventures [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

4,285

4,023

13,850

10,819

Unconsolidated Joint Ventures [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

1,899

1,874

5,713

5,598

Unconsolidated Joint Ventures [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

6,329

8,876

19,094

31,012

Company's Share [Member]

Segment Reporting Information [Line Items]

Net Operating Income

498,510

490,999

1,489,103

1,473,449

Company's Share [Member] | Boston [Member]

Segment Reporting Information [Line Items]

Net Operating Income

198,860

181,988

558,543

533,203

Company's Share [Member] | Los Angeles [Member]

Segment Reporting Information [Line Items]

Net Operating Income

18,152

12,508

57,974

38,501

Company's Share [Member] | New York [Member]

Segment Reporting Information [Line Items]

Net Operating Income

116,684

126,895

360,502

376,751

Company's Share [Member] | San Francisco [Member]

Segment Reporting Information [Line Items]

Net Operating Income

81,610

90,405

262,777

278,371

Company's Share [Member] | Seattle

Segment Reporting Information [Line Items]

Net Operating Income

9,338

12,563

28,211

41,563

Company's Share [Member] | Washington, DC [Member]

Segment Reporting Information [Line Items]

Net Operating Income

$ 73,866

$ 66,640

$ 221,096

$ 205,060

[1]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.
[2]	Rental Revenue is equal to Total Revenue per the Company’s Consolidated Statements of Operations, less Development and Management Services Revenue and Direct Reimbursements of Payroll and Related Costs from Management Services Contracts Revenue per the Consolidated Statements of Operations.

Investments in Unconsolidated Joint Ventures (Statements of Operations of the Joint Ventures) (Details) - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Schedule of Equity Method Investments [Line Items]

Total revenue

$ 859,227

$ 824,283

$ 2,549,148

$ 2,444,636

Expenses

Transaction costs

188

751

890

1,970

Depreciation and amortization

222,890

207,435

661,148

618,746

Total expenses

597,809

552,714

1,790,774

1,672,241

Other income (expense)

Interest expense

(163,194)

(147,812)

(474,727)

(424,492)

Net Loss

108,452

(103,543)

322,005

138,269

Income (Loss) from Equity Method Investments

(7,011)

(247,556)

6,376

(261,793)

Unconsolidated Joint Ventures [Member]

Schedule of Equity Method Investments [Line Items]

Total revenue

^[1]

128,435

153,551

378,981

469,745

Expenses

Operating

53,280

65,119

148,929

183,348

Transaction costs

179

Depreciation and amortization

41,082

49,840

118,901

151,051

Total expenses

94,415

115,037

267,891

334,578

Other income (expense)

Losses from early extinguishment of debt

(3)

Interest expense

(45,244)

(60,737)

(132,106)

(176,786)

Unrealized gain (loss) on derivative instruments

(19,172)

10,242

(8,212)

14,089

Net Loss

(30,396)

(11,981)

(29,228)

(27,533)

Company's share of net income (loss)

(9,319)

(4,476)

(9,105)

(10,739)

Gain on Unconsolidated Joint Venture Investment

35,756

^[2]

35,756

^[2]

Gain on sale / consolidation

21,696

Impairment loss on investment

(272,603)

^[3]

(272,603)

^[3]

Basis differential

^[4]

2,308

(6,233)

(6,215)

(14,207)

Income (Loss) from Equity Method Investments

(7,011)

(247,556)

6,376

(261,793)

Straight Line Rent Adjustments

2,600

7,700

16,500

20,900

Unconsolidated Joint Ventures [Member] | Basis Differential

Expenses

Depreciation and amortization

3,900

4,100

6,800

7,800

Other income (expense)

Straight Line Rent Adjustments

300

400

1,000

1,100

Above and below market rent adjustments, net

200

600

Derivative, Gain (Loss) on Derivative, Net

$ 5,100

2,700

$ 4,900

6,600

Unconsolidated Joint Ventures [Member] | Impairment Losses on Investments

Other income (expense)

Impairment loss on investment

$ 272,600

[1]	Includes straight-line rent adjustments of approximately $2.6 million and $7.7 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $16.5 million and $20.9 million for the nine months ended September 30, 2024 and 2023, respectively.
[2]	During the three months ended September 30, 2023, the Company completed a restructuring of its ownership in Metropolitan Square.
[3]	During the three and nine months ended September 30, 2023, the Company recognized an other-than-temporary impairment loss on its investments in Platform 16, 360 Park Avenue South, 200 Fifth Avenue and Safeco Plaza aggregating approximately $272.6 million.
[4]	Includes depreciation and amortization of approximately $3.9 million and $4.1 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $6.8 million and $7.8 million for the nine months ended September 30, 2024 and 2023, respectively. Includes unrealized loss on derivative instruments of approximately $5.1 million and $2.7 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $4.9 million and $6.6 million for the nine months ended September 30, 2024 and 2023, respectively. Includes straight-line rent adjustments of approximately $0.3 million and $0.4 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $1.0 million and $1.1 million for the nine months ended September 30, 2024 and 2023, respectively. Also includes net above-/below-market rent adjustments of approximately $0.2 million for the three months ended September 30, 2024 and 2023, and approximately $0.6 million for the nine months ended September 30, 2024 and 2023.

Cover - $ / shares	9 Months Ended
Cover - $ / shares	Sep. 30, 2024	Oct. 31, 2024
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	1-13087
Entity Registrant Name	BXP, INC.
Entity Central Index Key	0001037540
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2473675
Entity Address, Address Line One	Prudential Center, 800 Boylston Street, Suite 1900
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02199-8103
City Area Code	617
Local Phone Number	236-3300
Title of 12(b) Security	Common Stock, par value $0.01 per share
Entity Listing, Par Value Per Share	$ 0.01
Trading Symbol	BXP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		158,110,697
Boston Properties Limited Partnership
Entity Information [Line Items]
Document Type	10-Q
Document Period End Date	Sep. 30, 2024
Entity File Number	0-50209
Entity Registrant Name	BOSTON PROPERTIES LIMITED PARTNERSHIP
Entity Central Index Key	0001043121
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3372948
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false

Earnings Per Share / Common Unit

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Earnings Per Share / Common Unit

12. Earnings Per Share / Common Unit

BXP

The following table provides a reconciliation of both the net income (loss) attributable to BXP, Inc. and the number of common shares used in the computation of basic earnings per share (“EPS”), which is calculated by dividing net income (loss) attributable to BXP, Inc. by the weighted-average number of common shares outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic EPS of BXP using the two-class method. Participating securities are included in the computation of diluted EPS of BXP using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2021 MYLTIP Units required, and the 2022 - 2024 MYLTIP Units require, BXP to outperform certain performance thresholds, unless such thresholds have been met by the end of the applicable reporting period, BXP excludes such units from the diluted EPS calculation. Other potentially dilutive common shares, including stock options, restricted stock and other securities of BPLP that are exchangeable for BXP’s Common Stock, and the related impact on earnings, are considered when calculating diluted EPS.


	Three months ended September 30, 2024
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc.	$	83,628	157,725	$	0.53


Effect of Dilutive Securities:
Stock Based Compensation	—		488	—
Diluted Earnings:
Net income attributable to BXP, Inc.	$	83,628	158,213	$	0.53

	Three months ended September 30, 2023
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income (loss) attributable to BXP, Inc.	$	(111,826)	156,880	$	(0.71)


Effect of Dilutive Securities:
Stock Based Compensation	—		—	—
Diluted Earnings:
Net income (loss) attributable to BXP, Inc.	$	(111,826)	156,880	$	(0.71)


	Nine months ended September 30, 2024
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc. common shareholders	$	243,126	157,250	$	1.55


Effect of Dilutive Securities:
Stock Based Compensation	—		297	(0.01)
Diluted Earnings:
Net income attributable to BXP, Inc. common shareholders	$	243,126	157,547	$	1.54

	Nine months ended September 30, 2023
	Income (Numerator)		Shares (Denominator)	Per Share Amount
	(in thousands, except for per share amounts)
Basic Earnings:
Net income attributable to BXP, Inc. common shareholders	$	70,290	156,837	$	0.45


Effect of Dilutive Securities:
Stock Based Compensation	—		340	—
Diluted Earnings:
Net income attributable to BXP, Inc. common shareholders	$	70,290	157,177	$	0.45

BPLP

The following table provides a reconciliation of both the net income (loss) attributable to Boston Properties Limited Partnership and the number of common units used in the computation of basic earnings per common unit, which is calculated by dividing net income (loss) attributable to Boston Properties Limited Partnership by the weighted-average number of common units outstanding during the period. Unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are also participating securities. As such, unvested restricted common stock of BXP and BPLP’s LTIP Units, 2012 OPP Units and MYLTIP Units are considered participating securities. Participating securities are included in the computation of basic earnings per common unit using the two-class method. Participating securities are included in the computation of diluted earnings per common unit using the if-converted method if the impact is dilutive. Because the 2012 OPP Units and 2013 - 2021 MYLTIP Units required, and the 2022 - 2024 MYLTIP Units require, BXP to outperform certain performance thresholds, unless such thresholds have been met by the end of the applicable reporting period, BPLP excludes such units from the diluted earnings per common unit calculation. Other potentially dilutive common units and the related impact on earnings are considered when calculating diluted earnings per common unit. Included in the number of units (the denominator) below are approximately 17,721,000 and 18,002,000 redeemable common units for the three months ended September 30, 2024 and 2023, respectively, and 18,119,000 and 17,928,000 redeemable common units for the nine months ended September 30, 2024 and 2023, respectively.


	Three months ended September 30, 2024
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership	$	94,919	175,446	$	0.54


Effect of Dilutive Securities:
Stock Based Compensation	—		488	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership	$	94,919	175,934	$	0.54

	Three months ended September 30, 2023
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income (loss) attributable to Boston Properties Limited Partnership	$	(122,696)	174,882	$	(0.70)


Effect of Dilutive Securities:
Stock Based Compensation	—		—	—
Diluted Earnings:
Net income (loss) attributable to Boston Properties Limited Partnership	$	(122,696)	174,882	$	(0.70)


	Nine months ended September 30, 2024
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	276,826	175,369	$	1.58


Effect of Dilutive Securities:
Stock Based Compensation	—		297	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	276,826	175,666	$	1.58

	Nine months ended September 30, 2023
	Income (Numerator)		Units (Denominator)	Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	84,232	174,765	$	0.48


Effect of Dilutive Securities:
Stock Based Compensation	—		340	—
Diluted Earnings:
Net income attributable to Boston Properties Limited Partnership common unitholders	$	84,232	175,105	$	0.48

Earnings Per Share / Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic Earnings:
Net income attributable to the Company	$ 83,628	$ (111,826)	$ 243,126	$ 70,290
Net income (loss) attributable to the company (in shares / units)	157,725,000	156,880,000	157,250,000	156,837,000
Net income (loss) attributable to the company (in dollars per share / unit)	$ 0.53	$ (0.71)	$ 1.55	$ 0.45
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)	$ 0.53	$ (0.71)	$ 1.55	$ 0.45
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)	488,000	0	297,000	340,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0	$ (0.01)	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company	$ 83,628	$ (111,826)	$ 243,126	$ 70,290
Diluted Earnings: Net income attributable to the Company (in shares / units)	158,213,000	156,880,000	157,547,000	157,177,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.53	$ (0.71)	$ 1.54	$ 0.45
Boston Properties Limited Partnership
Redeemable Common Units	17,721,000	18,002,000	18,119,000	17,928,000
Basic Earnings:
Net income attributable to the Company	$ 94,919	$ (122,696)	$ 276,826	$ 84,232
Net income (loss) attributable to the company (in shares / units)	175,446,000	174,882,000	175,369,000	174,765,000
Net income (loss) attributable to the company (in dollars per share / unit)	$ 0.54	$ (0.70)	$ 1.58	$ 0.48
Earnings Per Share After Allocation of Undistributed Earnings to Participating Securities Basic (dollars per share)	$ 0.54	$ (0.70)	$ 1.58	$ 0.48
Effect of Dilutive Securities:
Stock Based Compensation	$ 0	$ 0	$ 0	$ 0
Stock Based Compensation (in shares / units)	488,000	0	297,000	340,000
Weighted Average Number Diluted Shares Outstanding Adjustment (per share)	$ 0	$ 0	$ 0	$ 0
Diluted Earnings:
Diluted Earnings: Net income attributable to the Company	$ 94,919	$ (122,696)	$ 276,826	$ 84,232
Diluted Earnings: Net income attributable to the Company (in shares / units)	175,934,000	174,882,000	175,666,000	175,105,000
Diluted Earnings: Net income, Per Share Amount (in dollars per share / unit)	$ 0.54	$ (0.70)	$ 1.58	$ 0.48

Commitments And Contingencies	9 Months Ended
Commitments And Contingencies	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	8. Commitments and Contingencies General In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence. In addition, in the normal course of business, the Company guarantees to certain tenants the obligations of the Company’s subsidiaries to pay tenant improvement allowances and brokerage commissions in connection with their leases and limited costs arising from delays in delivery of their premises. The Company had letter of credit and performance obligations related to lender and development requirements that total approximately $21.0 million at September 30, 2024. Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint venture. From time to time, under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, either the Company or its partners may be entitled to receive an additional promoted interest or payments. From time to time, the Company (or ventures in which the Company has an ownership interest) has agreed, and may in the future agree, to (1) guarantee portions of the principal, interest and other amounts in connection with their borrowings, (2) provide customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) in connection with their borrowings and (3) provide guarantees to lenders, tenants and other third parties for the completion of development projects. The Company has agreements with its third-party joint venture partners whereby the partners agree to reimburse the joint venture for their share of any payments made under the guarantee. In some cases, the Company earns a fee from the applicable joint venture for providing the guarantee. In connection with the refinancing of 767 Fifth Avenue’s (the General Motors Building) secured loan by the Company’s consolidated joint venture entity, 767 Venture, LLC, the Company guaranteed the consolidated entity’s obligation to fund various reserves for tenant improvement costs and allowances, leasing commissions and free rent obligations in lieu of cash deposits. As of September 30, 2024, the maximum funding obligation under the guarantee was approximately $6.4 million. The Company earns a fee from the joint venture for providing the guarantee and has an agreement with the outside partners to reimburse the joint venture for their share of any payments made under the guarantee. As of September 30, 2024, no amounts related to the guarantee were recorded as liabilities in the Company’s consolidated financial statements. In connection with the sale of Metropolitan Square, an approximately 657,000 square foot office building in Washington, DC in which the Company had a 20% equity interest, the Company agreed to become a co-lender of up to $20.0 million under a mezzanine loan. The mezzanine loan has a maximum principal amount of $100.0 million, and it is subordinate only to an existing senior loan. The mezzanine loan may be drawn upon for future lease-up, operating and other costs on an as-needed basis, and amounts borrowed will bear interest at a per annum rate of 12%, compounded monthly. As of September 30, 2024, the Company has funded approximately $3.9 million under the mezzanine loan. Legal Matters The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. Management believes that the final outcome of such matters will not have a material adverse effect on the financial position, results of operations or liquidity of the Company. In connection with the acquisition of an office property in New York City in 2010, the Company entered into an agreement with the seller pursuant to which the seller could earn various fees based on the future leasing performance of the property. The Company initially accrued approximately $1.5 million as an estimate of the fees it would owe the seller. In 2020, the seller filed suit against the Company in the Supreme Court of the State of New York, County of New York, claiming that consideration significantly in excess of the initial reserve amount is owed under the agreement. The disagreement between the Company and the seller involves material issues of contract interpretation and, more importantly, the method of calculating fees, including various inputs (both facts and assumptions) that drive the calculations. In February 2024, the court granted the seller’s motion for summary judgement interpreting certain sections of the agreement in favor of the seller’s claims. The Company is disputing the seller’s calculations and intends to continue defending itself vigorously. However, there can be no assurance that the Company will prevail in the lawsuit. If the court ultimately agrees with the seller’s calculations, then amounts due to the seller could theoretically be as high as the additional $31 million claimed in the seller’s complaint, plus interest. Although the Company disputes those calculations, there can be no assurance that the Company’s ultimate liability will not be significantly greater than its established accrual. On April 26, 2024, Brammer Bio MA, LLC (“Brammer”), a subsidiary of Thermo Fisher Scientific Inc. and an abutter to the Company’s 290 Binney Street development project located in Cambridge, Massachusetts, filed a complaint in Superior Court in Suffolk County, Massachusetts against the Company relating to certain ongoing construction activities. In the first quarter of 2023, the Company commenced development of 290 Binney Street, an approximately 573,000 net rentable square foot laboratory/life sciences property that is 100% pre-leased to AstraZeneca Pharmaceuticals (“AstraZeneca”). The Company has a 55% interest in the joint venture that owns 290 Binney Street. Brammer subleases the premises at 250 Binney Street, the Company’s approximately 67,000 net rentable square foot life sciences property that is adjacent to 290 Binney Street. Brammer alleges that, as a result of the Company’s construction of 290 Binney Street, it is threatened with irreparable harm due to intrusion onto the 250 Binney Street premises and the loss of its property rights. Brammer also alleges that the 290 Binney Street development project has caused and is causing major disruption to its manufacturing operations, and that it has suffered and will continue to suffer damages in the form of losses to its clients and customers. Brammer brought the action for quiet title, breach of contract, trespass and nuisance, and it is seeking declaratory and injunctive relief and specific performance purportedly to protect its property interests in the premises located at 250 Binney Street. The Company believes it has meritorious defenses against Brammer’s claims and intends to defend against them vigorously. However, there can be no assurance the Company will prevail in the litigation. If the Company is enjoined from further construction activities, it could suffer delays in construction that could result in its failure to deliver a completed building on the schedule contemplated by the Company’s lease with AstraZeneca or at all, and this could result in owing financial penalties to AstraZeneca and other third parties. Although the Company is unable to estimate a range of loss for all related matters for which losses are reasonably possible, if the court grants injunctive relief or awards monetary damages to Brammer, it could have a material adverse effect on the Company’s results of operations and financial condition. On May 16, 2024, Brammer’s motion for a preliminary injunction was denied by the trial court. Brammer subsequently appealed that decision, electing pursuant to Massachusetts civil procedure rules to petition for appeals to both a single justice of the Massachusetts Appeals Court and to a full appellate panel. On July 16, 2024, the single justice assigned to the appeal issued an order declining to rule on the substance of the appeal petition, which means that the appeal will be decided by the full panel. A date has not yet been set for the full panel hearing. Insurance The Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism other than nuclear, biological, chemical or radiological terrorism (“Terrorism Coverage”). The Company also carries $1.35 billion of property insurance in excess of the $1.0 billion of coverage in the Company’s property insurance program for 601 Lexington Avenue, New York, New York, consisting of $750 million of property and Terrorism Coverage in excess of the Company’s property insurance program and $600 million of Terrorism Coverage only in excess of the $1.75 billion of coverage. Certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), are currently insured in separate insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including Terrorism Coverage. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage for acts of terrorism certified under the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) (“NBCR Coverage”), which is provided by IXP as a direct insurer, for the properties in the Company’s portfolio, including 767 Fifth Avenue, but excluding certain other properties owned in joint ventures with third parties or which the Company manages. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the NBCR Coverage provided by IXP is backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $200 million, the coinsurance is 20% and the deductible is 20% of the premiums earned by the insurer for the year prior to a claim. If the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if TRIA is not extended after its expiration on December 31, 2027, if there is a change in its portfolio or for any other reason. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance. The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes. Specifically, the Company currently carries earthquake insurance which covers its San Francisco and Los Angeles regions with a $330 million per occurrence limit, and a $330 million annual aggregate limit, $30 million of which is provided by IXP, as a direct insurer. This insurance is subject to a deductible in the amount of 5% of the value of the affected property. In addition, the Company currently carries earthquake insurance which covers its Seattle region with a $110 million per occurrence limit, and a $110 million annual aggregate limit. This insurance is subject to a deductible in the amount of 2% of the value of the affected property. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance or change the structure of its earthquake insurance program on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage. IXP, a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco and Los Angeles properties and the Company’s NBCR Coverage. Insofar as the Company owns IXP, it is responsible for its liquidity and capital resources, and the accounts of IXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and its insurance policy is maintained after the payout by the Federal Government. If the Company experiences a loss and IXP is required to pay under its insurance policy, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance. In addition, BPLP has issued a guarantee to cover liabilities of IXP in the amount of $20.0 million. The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism, earthquakes, pandemics and cybersecurity incidents, in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to such losses and losses from acts of terrorism, earthquakes, pandemics or other catastrophic events, if the Company experiences a loss that is uninsured or that exceeds policy limits, the Company could lose the capital invested in the damaged properties, as well as the anticipated future revenues from those properties. Depending on the specific circumstances of each affected property, it is possible that the Company could be liable for mortgage indebtedness or other obligations related to the property. Any such loss could materially and adversely affect the Company’s business, financial condition and results of operations.

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss) Attributable to Parent	$ 83,628	$ (111,826)	$ 243,126	$ 70,290

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482765/220-10-50-6

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-8

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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-Paragraph 11
-Subparagraph (b)
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-URI https://asc.fasb.org/1943274/2147483443/250-10-50-11

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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-URI https://asc.fasb.org/1943274/2147483443/250-10-50-4

Reference 17: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479168/946-830-55-10

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479105/946-220-45-7

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(18))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Paragraph 1
-Subparagraph (SX 210.6-07(9))
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Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Paragraph 3
-Subparagraph (SX 210.6-09(1)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480097/470-10-S99-1A

Reference 23: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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Reference 27: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
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Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
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Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
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Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
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Reference 33: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
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-Publisher FASB
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Reference 35: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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-Subparagraph (a)
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Reference 37: http://fasb.org/us-gaap/role/ref/legacyRef
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-Paragraph 1
-Subparagraph (SX 210.9-04(22))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

+ Details

Unsecured Term Loans (Details) $ in Thousands						9 Months Ended
Unsecured Term Loans (Details) $ in Thousands	Sep. 30, 2024 USD ($) Rate	Sep. 27, 2024 USD ($) Rate	May 16, 2024	Apr. 29, 2024 USD ($)	Jan. 04, 2023 USD ($) mo	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Repayments of Unsecured Debt						$ 700,000	$ 500,000
Unsecured term loans, net	$ 798,058					798,058		$ 1,198,301
Borrowings on unsecured term loans						0	1,200,000
Repayment of unsecured term loans						$ 500,000	$ 730,000
Santa Monica Business Park [Member]
Debt Instrument [Line Items]
Debt		$ 200,000
Maximum [Member] \| Santa Monica Business Park [Member] \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	2.688%					2.688%
Minimum [Member] \| Santa Monica Business Park [Member] \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	2.661%					2.661%
Daily Simple Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate	1.05%
2023 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity					$ 1,200,000
Line of Credit, Additional Borrowing Capacity					$ 300,000
Number of extensions					1
Extension Option (in months) \| mo					12
Unsecured term loans, net	$ 700,000					$ 700,000
Borrowings on unsecured term loans					$ 1,200,000
Repayment of unsecured term loans				$ 500,000
2023 Unsecured Term Loan \| Extended Maturity
Debt Instrument [Line Items]
Debt Instrument, Maturity Date			May 16, 2025		May 16, 2024
2023 Unsecured Term Loan \| Minimum [Member]
Debt Instrument [Line Items]
Number of Additional Term Loans					1
2024 Unsecured Term Loan
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 100,000
Number of extensions		3
Debt Instrument, Interest Rate Terms		loans under the 2024 Unsecured Term Loan will bear interest at a rate per annum equal to (1) a base rate equal to the highest of (a) zero, (b) Prime Rate, (c) the Federal Funds effective rate plus 0.50%, and (d) Term SOFR for a one-month period plus 1.10%, in each case, plus a margin ranging from 0 to 60 basis points based on BPLP’s credit rating; or (2) a rate equal to adjusted Term SOFR or Daily Simple SOFR with a one-month period plus a margin ranging from 75 to 160 basis points based on BPLP’s credit rating.
Borrowings on unsecured term loans		$ 100,000
Debt	$ 100,000					$ 100,000
Extension Option (in years)		1
2024 Unsecured Term Loan \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate \| Rate		2.688%
2024 Unsecured Term Loan \| Maximum [Member] \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	2.688%					2.688%
2024 Unsecured Term Loan \| Minimum [Member] \| Interest Rate Swap
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	2.688%					2.688%
2024 Unsecured Term Loan \| Fed Funds Effective Rate Overnight Index Swap Rate
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.50%
2024 Unsecured Term Loan \| Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage \| Rate		0.00%
2024 Unsecured Term Loan \| Base Rate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.60%
2024 Unsecured Term Loan \| Base Rate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.00%
2024 Unsecured Term Loan \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		1.10%
2024 Unsecured Term Loan \| Daily Simple Secured Overnight Financing Rate (SOFR) \| Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		1.60%
2024 Unsecured Term Loan \| Daily Simple Secured Overnight Financing Rate (SOFR) \| Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate \| Rate		0.75%

Noncontrolling Interests (Property Partnerships) (Narrative) (Details) $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 21, 2024 USD ($)	Sep. 30, 2024 USD ($) ft²	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) ft²	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Jan. 05, 2023 ft²
Noncontrolling Interest [Line Items]
Noncontrolling Interest in Limited Partnerships		$ 1,874,272		$ 1,874,272		$ 1,640,704
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships		$ 95,724	$ 22,635	$ 306,147	$ 30,190
Construction in Progress
Noncontrolling Interest [Line Items]
Net Rentable Area (in sf) \| ft²		2,700,000		2,700,000
290 Binney
Noncontrolling Interest [Line Items]
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	$ 97,200
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	104,600	$ (27,100)		$ 7,800
Difference Between Proceeds from Sale and Noncontrolling Interest	$ 7,500
Percent of Carrying Value of Real Estate, Gross	45.00%
290 Binney \| Construction in Progress \| Office and Life Sciences Building [Member]
Noncontrolling Interest [Line Items]
Net Rentable Area (in sf) \| ft²		573,000		573,000			573,000
Leased percentage		100.00%		100.00%			100.00%
290 Binney \| Noncontrolling Interest [Member] \| Consolidated Joint Venture Partner
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	45.00%
290 Binney \| Noncontrolling Interest [Member] \| Company's Share [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent	55.00%

Consolidated Statement of Capital and Noncontrolling Interests - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Common Stock, Shares, Outstanding	157,979,898		157,979,898			156,940,866
Effective portion of interest rate contracts	$ (32,263)	$ 5,459	$ (14,976)	$ 13,886
Amortization of interest rate contracts	3,077	1,677	9,518	5,026
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	95,724	22,635	306,147	30,190
Distributions to noncontrolling interests in property partnerships	$ (14,894)	$ (12,150)	$ (52,353)	$ (48,370)
General Partner [Member]
Common Stock, Shares, Outstanding	1,762,000	1,755,000	1,762,000	1,755,000	1,762,000	1,755,000	1,755,000	1,750,000
Net activity from contributions and unearned compensation	0	0	5,000	5,000
Conversion of redeemable partnership units			2,000	0
Limited Partner [Member]
Common Stock, Shares, Outstanding	156,217,000	155,184,000	156,217,000	155,184,000	155,336,000	155,185,000	155,098,000	155,008,000
Net activity from contributions and unearned compensation	6,000	7,000	82,000	76,000
Conversion of redeemable partnership units	875,000	79,000	950,000	100,000
Partners' Capital (General and Limited Partners)[Member]
Beginning Balance	$ 4,685,471	$ 5,036,445	$ 4,685,471	$ 5,036,445	$ 5,010,460	$ 4,973,951	$ 5,351,166	$ 5,299,428
Net activity from contributions and unearned compensation, value	(1,232)	991	4,129	4,913
Allocated net income for the period	85,332	(110,169)	248,230	75,590
Distributions	(154,820)	(153,800)	(462,684)	(461,209)
Conversion of redeemable partnership units, value	30,992	2,920	33,746	3,714
Adjustment to reflect redeemable partnership units at redemption value	(308,876)	(54,663)	(182,842)	114,009
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	23,615		70,941
Accumulated Other Comprehensive Loss [Member]
Beginning Balance	(26,428)	2,866	(26,428)	2,866	(155)	(21,147)	(3,406)	(13,718)
Effective portion of interest rate contracts	(28,910)	4,896	(13,429)	12,461
Amortization of interest rate contracts	2,637	1,376	8,148	4,123
Noncontrolling interest - property partnerships [Member]
Beginning Balance	1,874,272	1,588,906	1,874,272	1,588,906	1,801,676	1,640,704	1,557,368	1,547,317
Allocated net income for the period	15,237	20,909	50,283	59,337
Amortization of interest rate contracts	144	144	432	432
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	72,109	22,635	235,206	30,190
Distributions to noncontrolling interests in property partnerships	(14,894)	(12,150)	(52,353)	(48,370)
Total Capital [Member]
Beginning Balance	6,533,315	6,628,217	6,533,315	6,628,217	6,811,981	6,593,508	6,905,128	6,833,027
Net activity from contributions and unearned compensation, value	(1,232)	991	4,129	4,913
Allocated net income for the period	100,569	(89,260)	298,513	134,927
Distributions	(154,820)	(153,800)	(462,684)	(461,209)
Conversion of redeemable partnership units, value	30,992	2,920	33,746	3,714
Adjustment to reflect redeemable partnership units at redemption value	(308,876)	(54,663)	(182,842)	114,009
Effective portion of interest rate contracts	(28,910)	4,896	(13,429)	12,461
Amortization of interest rate contracts	2,781	1,520	8,580	4,555
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	95,724	22,635	306,147	30,190
Distributions to noncontrolling interests in property partnerships	(14,894)	(12,150)	(52,353)	(48,370)
Noncontrolling interest - Redeemable partnership units [Member]
Beginning Balance	1,500,501	1,160,753	1,500,501	1,160,753	$ 1,230,848	$ 1,347,575	$ 1,135,053	$ 1,280,886
Net activity from contributions and unearned compensation, value	3,225	4,065	31,535	42,090
Allocated net income for the period	9,587	(12,527)	28,596	8,642
Distributions	(17,986)	(18,301)	(55,692)	(55,038)
Conversion of redeemable partnership units, value	(30,992)	(2,920)	(33,746)	(3,714)
Adjustment to reflect redeemable partnership units at redemption value	308,876	54,663	182,842	(114,009)
Effective portion of interest rate contracts	(3,353)	563	(1,547)	1,425
Amortization of interest rate contracts	$ 296	$ 157	$ 938	$ 471

Investments in Unconsolidated Joint Ventures (Balance Sheets of the Unconsolidated Joint Ventures) (Details) - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

ASSETS

Total real estate

$ 20,900,979

$ 20,593,459

Total assets

26,405,536

26,026,149

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Mortgage and notes payable, net

4,275,155

4,166,379

Other Liabilities

407,441

445,947

Members’/Partners’ equity

5,759,209

5,876,697

Total liabilities and equity / capital

26,405,536

26,026,149

Carying value of the Company's investment in unconsolidated joint ventures

1,421,886

1,377,319

Operating Lease, Right-of-Use Asset

^[1]

339,804

324,298

Lease Liabilities - Operating Leases

389,444

350,391

Unconsolidated Joint Ventures [Member]

ASSETS

Total real estate

^[2]

5,756,008

5,811,763

Other assets

^[3]

651,956

682,291

Total assets

6,407,964

6,494,054

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Mortgage and notes payable, net

3,198,547

3,351,873

Other Liabilities

^[4]

294,795

361,357

Members’/Partners’ equity

2,914,622

2,780,824

Total liabilities and equity / capital

6,407,964

6,494,054

Company's share of equity

1,334,102

1,278,483

Basis differentials

^[5]

57,047

58,933

Carying value of the Company's investment in unconsolidated joint ventures

^[6]

1,391,149

1,337,416

Operating Lease, Right-of-Use Asset

19,200

20,100

Sales-type lease receivable, net

14,100

13,900

Lease Liabilities - Operating Leases

30,500

Unconsolidated Joint Ventures [Member]

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Other Liabilities

30,700

39,900

Colorado Center

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

296,758

298,906

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

234,972

237,815

200 Fifth Avenue JV LLC

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

51,779

58,308

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

68,563

75,718

Gateway Commons Complex [Member]

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

51,009

48,971

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

393,679

376,834

Safeco Plaza REIT LLC

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

(29,032)

(29,678)

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

47,510

44,734

360 PAS Holdco LLC

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

(114,202)

(116,534)

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

69,538

42,988

Dock 72

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Other Liabilities

^[7]

7,065

11,890

Basis differentials

(92,930)

(95,521)

Platform 16

LIABILITIES AND MEMBERS'/PARTNERS' EQUITY

Basis differentials

(142,670)

(143,052)

Carying value of the Company's investment in unconsolidated joint ventures

^[7]

$ 55,381

$ 45,564

[1]

See Note 4.

[2]

At September 30, 2024 and December 31, 2023, this amount included right of use assets - operating leases totaling approximately $19.2 million and $20.1 million, respectively.

[3]

At September 30, 2024 and December 31, 2023, this amount included sales-type lease receivable, net totaling approximately $14.1 million and $13.9 million, respectively.

[4]

At September 30, 2024 and December 31, 2023, this amount included lease liabilities - operating leases totaling approximately $30.5 million.

[5]

This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The Company’s basis differences include:


	September 30, 2024		December 31, 2023
Property	(in thousands)
Colorado Center	$	296,758	$	298,906
200 Fifth Avenue	51,779		58,308
Gateway Commons	51,009		48,971
Safeco Plaza	(29,032)		(29,678)
360 Park Avenue South	(114,202)		(116,534)
Dock 72	(92,930)		(95,521)
Platform 16	(142,670)		(143,052)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

[6]

Investments with deficit balances aggregating approximately $30.7 million and $39.9 million at September 30, 2024 and December 31, 2023, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

[7]

Investments with deficit balances aggregating approximately $30.7 million and $39.9 million at September 30, 2024 and December 31, 2023, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.

2024 and 2023 Unsecured Term Loan Compliance (Details) - 2024 Unsecured Term Loan and 2023 Unsecured Term Loan		9 Months Ended
	Sep. 27, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
Debt Instrument, Covenant Description	Among other covenants, the 2023 and 2024 Unsecured Term Loans require that BPLP maintain on an ongoing basis: (1) a leverage ratio not to exceed 60%, however, the leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within one year, (2) a secured debt leverage ratio not to exceed 55%, (3) a fixed charge coverage ratio of at least 1.40 to 1.00, (4) an unsecured debt leverage ratio not to exceed 60%, however, the unsecured debt leverage ratio may increase to no greater than 65% provided that it is reduced to 60% within one year, (5) an unsecured debt interest coverage ratio of at least 1.75 to 1.00 and (6) limitations on permitted investments.
Leverage ratio	60.00%
Leverage ratio - maximum	65.00%
Secured debt leverage ratio - maximum	55.00%
Fixed charge coverage - maximum	1.40
Fixed charge coverage - minimum	1.00
Unsecured debt leverage ratio	60.00%
Unsecured debt leverage ratio - maximum	65.00%
Debt Instrument, Covenant Compliance		At September 30, 2024, BPLP was in compliance with each of these financial and other covenant requirements.
Minimum [Member]
Debt Instrument [Line Items]
Unsecured debt interest coverage ratio	1.00
Maximum [Member]
Debt Instrument [Line Items]
Unsecured debt interest coverage ratio	1.75

Leases (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Fixed contractual payments	$ 646,979	$ 626,738	$ 1,947,599	$ 1,877,573
Variable lease payments	152,242	140,210	430,279	407,528
Sales-type lease revenue	250	233	738	688
Lease	$ 799,471	$ 767,181	$ 2,378,616	$ 2,285,789

Organization (Details) ft² in Millions		3 Months Ended	9 Months Ended
Organization (Details) ft² in Millions	Dec. 31, 2023	Sep. 30, 2024 ft² Real_Estate_Properties yr shares	Sep. 30, 2024 ft² Real_Estate_Properties yr shares
Real Estate Properties [Line Items]
Restriction on redemption of OP units from date of issuance (years) \| yr		1	1
One OP unit is equivalent to one share of Common Stock (in shares) \| shares		1	1
OP unit conversion rate (in shares) \| shares		1	1
2012 OPP Units and Vested MYLTIPs
Real Estate Properties [Line Items]
Vesting Period			3 years
Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		9	9
Net Rentable Area (in sf) \| ft²		2.7	2.7
Commercial Real Estate Properties [Member]
Real Estate Properties [Line Items]
Number of real estate properties		184	184
Net Rentable Area (in sf) \| ft²		53.0	53.0
Office and Life Sciences Building [Member]
Real Estate Properties [Line Items]
Number of real estate properties		162	162
Office and Life Sciences Building [Member] \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		6	6
Retail Site [Member]
Real Estate Properties [Line Items]
Number of real estate properties		14	14
Retail Site [Member] \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		1	1
Residential Building
Real Estate Properties [Line Items]
Number of real estate properties		7	7
Residential Building \| Construction in Progress
Real Estate Properties [Line Items]
Number of real estate properties		2	2
Hotel [Member]
Real Estate Properties [Line Items]
Number of real estate properties		1	1
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
General and limited partnership interest in the operating partnership (percent)	89.40%	89.60%

Stockholders' Equity / Partners' Capital (Tables)

9 Months Ended

Sep. 30, 2024

Class of Stock [Line Items]

Dividends Declared [Table Text Block]

The following table presents BXP’s dividends per share and BPLP’s distributions per OP Unit and LTIP Unit paid or declared in 2024 and during the nine months ended September 30, 2023:


Record Date	Payment Date	Dividend (Per Share)	Distribution (Per Unit)
September 30, 2024	October 31, 2024	$0.98	$0.98
June 28, 2024	July 31, 2024	$0.98	$0.98
March 28, 2024	April 30, 2024	$0.98	$0.98
December 29, 2023	January 30, 2024	$0.98	$0.98
September 29, 2023	October 31, 2023	$0.98	$0.98
June 30, 2023	July 31, 2023	$0.98	$0.98
March 31, 2023	April 28, 2023	$0.98	$0.98
December 30, 2022	January 30, 2023	$0.98	$0.98

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 505
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Consolidated Balance Sheets - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

ASSETS

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

$ 27,557,824

$ 26,749,209

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

372,896

401,680

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

^[1]

339,804

324,298

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(7,369,545)

(6,881,728)

Total real estate

20,900,979

20,593,459

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

1,420,475

1,531,477

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

51,009

81,090

Investments in securities

39,186

36,337

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

99,706

122,407

Note receivable, net

3,937

1,714

Sales-type lease receivable, net

14,429

13,704

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

1,438,492

1,355,212

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

794,571

760,421

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

132,078

64,230

Investments in unconsolidated joint ventures

1,421,886

1,377,319

Total assets

26,405,536

26,026,149

Liabilities:

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

4,275,155

4,166,379

Unsecured senior notes, net

10,642,033

10,491,617

Unsecured line of credit

Unsecured term loans, net

798,058

1,198,301

Unsecured commercial paper

500,000

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

373,260

417,961

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

389,444

350,391

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

444,288

458,329

Dividends and distributions payable

172,191

171,176

Accrued interest payable

121,360

133,684

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

407,441

445,947

Total liabilities

18,123,230

17,833,785

Redeemable deferred stock units— 132,930 and 119,471 units outstanding at redemption value at September 30, 2024 and December 31, 2023, respectively

$ 10,696

$ 8,383

Excess stock, shares outstanding

Excess stock, shares issued

Preferred stock / units, shares / units issued (in shares / units)

Preferred stock / units, shares / units outstanding (in shares / units)

Equity / Capital:

Excess stock, $0.01 par value, 150,000,000 shares authorized, none issued or outstanding

$ 0

Preferred stock, $0.01 par value, 50,000,000 shares authorized, none issued or outstanding

Common stock, $0.01 par value, 250,000,000 shares authorized, 158,058,798 and 157,019,766 issued and 157,979,898 and 156,940,866 outstanding at September 30, 2024 and December 31, 2023, respectively

1,580

1,569

Additional paid-in capital

6,822,489

6,715,149

Dividends in excess of earnings

$ (1,035,710)

$ (816,152)

Treasury common stock at cost, shares

78,900

Treasury common stock at cost, 78,900 shares at September 30, 2024 and December 31, 2023

$ (2,722)

Accumulated other comprehensive loss

(26,428)

(21,147)

Total stockholders' equity attributable to Boston Properties, Inc.

5,759,209

5,876,697

Noncontrolling interests:

Common units of the Operating Partnership

638,129

666,580

Property partnerships

1,874,272

1,640,704

Total equity / capital

8,271,610

8,183,981

Total liabilities and equity / capital

26,405,536

26,026,149

Related Party

ASSETS

Related party notes receivable, net

88,788

88,779

Variable Interest Entity, Primary Beneficiary [Member]

ASSETS

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

7,646,435

7,054,075

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

21,000

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

145,052

158,885

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(1,601,919)

(1,501,483)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

322,604

245,317

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

5,032

22,160

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

19,216

27,987

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

425,867

401,159

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

201,947

175,383

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

50,275

11,824

Liabilities:

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

3,280,817

3,277,185

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

20,897

20,794

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

154,637

145,826

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

120,092

59,667

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

89,876

115,275

Boston Properties Limited Partnership

ASSETS

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

27,191,559

26,382,944

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

372,896

401,680

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

^[1]

339,804

324,298

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(7,241,074)

(6,758,361)

Total real estate

20,663,185

20,350,561

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

1,420,475

1,531,477

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

51,009

81,090

Investments in securities

39,186

36,337

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

99,706

122,407

Note receivable, net

3,937

1,714

Sales-type lease receivable, net

14,429

13,704

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

1,438,492

1,355,212

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

794,571

760,421

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

132,078

64,230

Investments in unconsolidated joint ventures

1,421,886

1,377,319

Total assets

26,167,742

25,783,251

Liabilities:

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

4,275,155

4,166,379

Unsecured senior notes, net

10,642,033

10,491,617

Unsecured line of credit

Unsecured term loans, net

798,058

1,198,301

Unsecured commercial paper

500,000

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

373,260

417,961

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

389,444

350,391

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

444,288

458,329

Dividends and distributions payable

172,191

171,176

Accrued interest payable

121,360

133,684

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

407,441

445,947

Total liabilities

18,123,230

17,833,785

Redeemable deferred stock units— 132,930 and 119,471 units outstanding at redemption value at September 30, 2024 and December 31, 2023, respectively

10,696

8,383

Noncontrolling interest:

Redeemable partnership units— 15,926,014 and 16,508,277 common units and 2,336,797 and 2,065,861 long term incentive units outstanding at redemption value at September 30, 2024 and December 31, 2023, respectively

1,500,501

1,347,575

Equity / Capital:

Boston Properties Limited Partnership partners’ capital— 1,762,427 and 1,755,150 general partner units and 156,217,471 and 155,185,716 limited partner units outstanding at September 30, 2024 and December 31, 2023, respectively

4,685,471

4,973,951

Accumulated other comprehensive loss

(26,428)

(21,147)

Total partners’ capital

4,659,043

4,952,804

Noncontrolling interests in property partnerships

1,874,272

1,640,704

Noncontrolling interests:

Total equity / capital

6,533,315

6,593,508

Total liabilities and equity / capital

26,167,742

25,783,251

Boston Properties Limited Partnership | Related Party

ASSETS

Related party notes receivable, net

88,788

88,779

Boston Properties Limited Partnership | Variable Interest Entity, Primary Beneficiary [Member]

ASSETS

Real estate, at cost (amounts related to variable interest entities (“VIEs”) of $7,646,435 and $7,054,075 at September 30, 2024 and December 31, 2023, respectively)

7,646,435

7,054,075

Right of use assets - finance leases (amounts related to VIEs of $21,000 and $21,000 at September 30, 2024 and December 31, 2023, respectively)

21,000

Right of use assets - operating leases (amounts related to VIEs of $145,052 and $158,885 at September 30, 2024 and December 31, 2023, respectively)

145,052

158,885

Less: accumulated depreciation (amounts related to VIEs of $(1,601,919) and $(1,501,483) at September 30, 2024 and December 31, 2023, respectively)

(1,601,919)

(1,501,483)

Cash and cash equivalents (amounts related to VIEs of $322,604 and $245,317 at September 30, 2024 and December 31, 2023, respectively)

322,604

245,317

Cash held in escrows (amounts related to VIEs of $5,032 and $22,160 at September 30, 2024 and December 31, 2023, respectively)

5,032

22,160

Tenant and other receivables, net (amounts related to VIEs of $19,216 and $27,987 at September 30, 2024 and December 31, 2023, respectively)

19,216

27,987

Accrued rental income, net (amounts related to VIEs of $425,867 and $401,159 at September 30, 2024 and December 31, 2023, respectively)

425,867

401,159

Deferred charges, net (amounts related to VIEs of $201,947 and $175,383 at September 30, 2024 and December 31, 2023, respectively)

201,947

175,383

Prepaid expenses and other assets (amounts related to VIEs of $50,275 and $11,824 at September 30, 2024 and December 31, 2023, respectively)

50,275

11,824

Liabilities:

Mortgage notes payable, net (amounts related to VIEs of $3,280,817 and $3,277,185 at September 30, 2024 and December 31, 2023, respectively)

3,280,817

3,277,185

Lease liabilities - finance leases (amounts related to VIEs of $20,897 and $20,794 at September 30, 2024 and December 31, 2023, respectively)

20,897

20,794

Lease liabilities - operating leases (amounts related to VIEs of $154,637 and $145,826 at September 30, 2024 and December 31, 2023, respectively)

154,637

145,826

Accounts payable and accrued expenses (amounts related to VIEs of $120,092 and $59,667 at September 30, 2024 and December 31, 2023, respectively)

120,092

59,667

Other liabilities (amounts related to VIEs of $89,876 and $115,275 at September 30, 2024 and December 31, 2023, respectively)

$ 89,876

$ 115,275

[1]	See Note 4.

Real Estate Weighted-Average Useful Life of Intangible Assets by Major Class (Details) - 901 New York Avenue	Jan. 08, 2024
In-Place Lease Intangibles
Real Estate Properties [Line Items]
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life	6 years 8 months 12 days
Above Market Lease Intangibles [Member]
Real Estate Properties [Line Items]
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life	4 years
Below Market Lease [Member]
Real Estate Properties [Line Items]
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life	9 years 9 months 18 days

Summary Of Significant Accounting Policies (Carrying Value Of Indebtedness And Corresponding Estimate Of Fair Value) (Details) - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

Summary Of Significant Accounting Policies [Line Items]

Note receivable, net

$ 3,937

$ 1,714

Sales-type lease receivable, net

14,429

13,704

Mortgage notes payable, net

4,275,155

4,166,379

Unsecured senior notes, net

10,642,033

10,491,617

Unsecured line of credit

Unsecured term loan, net

798,058

1,198,301

Unsecured commercial paper

500,000

Related party notes receivable, net

88,788

88,779

Carrying Amount [Member]

Summary Of Significant Accounting Policies [Line Items]

3-Month United States Treasury Bills

^[1]

175,944

302,746

Sales-type lease receivable, net

14,429

13,704

Total

107,154

104,197

Mortgage notes payable, net

4,275,155

4,166,379

Unsecured senior notes, net

10,642,033

10,491,617

Unsecured line of credit

Unsecured term loan, net

798,058

1,198,301

Unsecured commercial paper

500,000

Total

16,215,246

15,856,297

Carrying Amount [Member] | Related Party

Summary Of Significant Accounting Policies [Line Items]

Related party notes receivable, net

88,788

88,779

Carrying Amount [Member] | Nonrelated Party

Summary Of Significant Accounting Policies [Line Items]

Note receivable, net

3,937

1,714

Estimated Fair Value [Member]

Summary Of Significant Accounting Policies [Line Items]

3-Month United States Treasury Bills

^[1]

175,944

302,746

Sales-type lease receivable, net

13,563

13,338

Total

108,500

105,608

Mortgage notes payable, net

3,907,688

3,705,513

Unsecured senior notes, net

10,191,058

9,697,393

Unsecured line of credit

Unsecured term loan, net

800,303

1,196,945

Unsecured commercial paper

500,000

Total

15,399,049

14,599,851

Estimated Fair Value [Member] | Related Party

Summary Of Significant Accounting Policies [Line Items]

Related party notes receivable, net

90,138

90,593

Estimated Fair Value [Member] | Nonrelated Party

Summary Of Significant Accounting Policies [Line Items]

Note receivable, net

$ 4,799

$ 1,677

[1]	Per the guidance in ASC 326 “Financial Instruments — Credit Losses” (“ASC 326”), the Company concluded that the risk of nonpayment is nonexistent because the U.S. Government has a long history with no credit losses and, therefore, no credit loss allowance was recorded.

Stockholders' Equity / Partners' Capital Narrative (Details) $ in Millions		9 Months Ended
	May 17, 2023 USD ($) yr	Sep. 30, 2024 shares	Dec. 31, 2023 shares	May 22, 2020 USD ($)
Class of Stock [Line Items]
Common Stock, Shares, Outstanding		157,979,898	156,940,866
General Partners' Capital Account, Units Outstanding (in units)		1,762,427
Limited Partners' Capital Account, Units Outstanding (in units)		156,217,471
Shares of Common Stock issued in connection with redemption of an equal number of OP Units (in shares)		951,881
Common stock, shares issued		158,058,798	157,019,766
ATM Program [Member]
Class of Stock [Line Items]
At The Market Stock Offering Program Aggregate Value Of Common Stock \| $	$ 600.0			$ 600.0
At Market Stock Offering Program Maximum Length Of Sale (in years) \| yr	3
Common stock, shares issued		0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Lessee - Leases Narrative (Details)
$ in Thousands

3 Months Ended

6 Months Ended

9 Months Ended

Sep. 30, 2024

USD ($)

Sep. 30, 2023

USD ($)

Sep. 30, 2024

USD ($)

Sep. 30, 2024

USD ($)

Sep. 30, 2023

USD ($)

May 01, 2024

USD ($)

ft²

Mar. 28, 2024

USD ($)

ft²

Dec. 31, 2023

USD ($)

Lessee, Lease, Description [Line Items]

Operating Lease, Payments

$ 390

$ (282)

Operating Lease, Right-of-Use Asset

^[1]

$ 339,804

339,804

$ 324,298

Lease liabilities - finance leases

373,260

417,961

Finance Lease, Right-of-Use Asset

372,896

$ 401,680

Interest expense

(163,194)

$ (147,812)

(474,727)

$ (424,492)

171 Dartmouth Street air rights [Member]

Lessee, Lease, Description [Line Items]

Lessee, Operating Lease, Term of Contract

90 years

Lessee, Operating Lease, Discount Rate

6.57%

Net Present Value and Operating Lease Liability

$ 23,200

Operating Lease, Right-of-Use Asset

$ 23,900

Operating lease costs

$ 87

$ 200

Land Subject to Ground Leases | ft²

61,000

171 Dartmouth Street air rights [Member] | Base Rental Payment [Member]

Lessee, Lease, Description [Line Items]

Operating Leases, Future Minimum Payments Due

$ 250

171 Dartmouth Street air rights [Member] | Additional Rental Payment

Lessee, Lease, Description [Line Items]

Operating Leases, Future Minimum Payments Due

$ 500

The Skylyne

Lessee, Lease, Description [Line Items]

Lessee, Finance Lease, Remaining Lease Term

92 years

Purchase Options, Land

$ 38,700

Lease liabilities - finance leases

100

Finance Lease, Right-of-Use Asset

$ 0

Interest expense

$ 9,500

The Skylyne | Residential Building

Lessee, Lease, Description [Line Items]

Net Rentable Area (in sf) | ft²

331,000

Number of Units in Real Estate Property

402

[1]	See Note 4.

Investments in Unconsolidated Joint Ventures

9 Months Ended

Sep. 30, 2024

Equity Method Investments and Joint Ventures [Abstract]

Investments In Unconsolidated Joint Ventures

5. Investments in Unconsolidated Joint Ventures

The investments in unconsolidated joint ventures consist of the following at September 30, 2024 and December 31, 2023:


					Carrying Value of Investment (1)
Entity	Properties	Nominal % Ownership			September 30, 2024		December 31, 2023
					(in thousands)
Square 407 Limited Partnership	Market Square North	50.00	%		$	(12,042)	$	(5,996)
901 New York, LLC	901 New York Avenue	25.00	%	(2)	—		(11,764)
WP Project Developer LLC	Wisconsin Place Land and Infrastructure	33.33	%	(3)	29,969		30,375
500 North Capitol Venture LLC	500 North Capitol Street, NW	30.00	%		(11,630)		(10,253)
501 K Street LLC	1001 6th Street	50.00	%		45,955		44,774
Podium Developer LLC	The Hub on Causeway - Podium	50.00	%		42,916		45,201
Residential Tower Developer LLC	Hub50House	50.00	%		38,116		40,235
Hotel Tower Developer LLC	The Hub on Causeway - Hotel Air Rights	50.00	%		14,076		13,494
Office Tower Developer LLC	100 Causeway Street	50.00	%		56,055		57,660
1265 Main Office JV LLC	1265 Main Street	50.00	%		3,515		3,585
BNY Tower Holdings LLC	Dock 72	50.00	%	(4)	(7,065)		(11,890)

CA-Colorado Center, LLC	Colorado Center	50.00	%		234,972		237,815
7750 Wisconsin Avenue LLC	7750 Wisconsin Avenue	50.00	%		48,814		50,064
BP-M 3HB Venture LLC	3 Hudson Boulevard	25.00	%		113,288		115,103
Platform 16 Holdings LP	Platform 16	55.00	%		55,381		45,564
Gateway Portfolio Holdings LLC	Gateway Commons	50.00	%		393,679		376,834
Rosecrans-Sepulveda Partners 4, LLC	Beach Cities Media Campus	50.00	%		27,051		27,034
Safeco Plaza REIT LLC	Safeco Plaza	33.67	%	(5)	47,510		44,734
360 PAS Holdco LLC	360 Park Avenue South	71.11	%	(6)	69,538		42,988
PR II/BXP Reston Gateway LLC	Skymark - Reston Next Residential	20.00	%		15,359		15,184
751 Gateway Holdings LLC	751 Gateway	49.00	%		98,882		93,411
200 Fifth Avenue JV LLC	200 Fifth Avenue	26.69	%		68,563		75,718
ABXP Worldgate Investments LLC	13100 and 13150 Worldgate Drive	50.00	%		18,247		17,546
					$	1,391,149	$	1,337,416

_______________

(1)Investments with deficit balances aggregating approximately $30.7 million and $39.9 million at September 30, 2024 and December 31, 2023, respectively, are included within Other Liabilities in the Company’s Consolidated Balance Sheets.

(2)At December 31, 2023, the Company’s economic ownership was approximately 50%. On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest for a gross purchase price of

$10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.

(3)The Company’s wholly-owned subsidiary that owns Wisconsin Place Office also owns a 33.33% interest in the joint venture entity that owns the land, parking garage and infrastructure of the project.

(4)This property includes net equity balances from the amenity joint venture.

(5)The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.

(6)The Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 35.02% indirect ownership in the joint venture, and (3) an additional 1% interest in the entity through which the partner owns its interest in the joint venture.

Certain of the Company’s unconsolidated joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. Under certain of the Company’s joint venture agreements, if certain return thresholds are achieved, the partners or the Company will be entitled to an additional promoted interest or payments.

The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows:


	September 30, 2024		December 31, 2023
	(in thousands)
ASSETS
Real estate and development in process, net (1)	$	5,756,008	$	5,811,763
Other assets (2)	651,956		682,291
Total assets	$	6,407,964	$	6,494,054
LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY
Mortgage and notes payable, net	$	3,198,547	$	3,351,873
Other liabilities (3)	294,795		361,357
Members’/Partners’ equity	2,914,622		2,780,824
Total liabilities and members’/partners’ equity	$	6,407,964	$	6,494,054
Company’s share of equity	$	1,334,102	$	1,278,483
Basis differentials (4)	57,047		58,933
Carrying value of the Company’s investments in unconsolidated joint ventures (5)	$	1,391,149	$	1,337,416

_______________

(1)At September 30, 2024 and December 31, 2023, this amount included right of use assets - operating leases totaling approximately $19.2 million and $20.1 million, respectively.

(2)At September 30, 2024 and December 31, 2023, this amount included sales-type lease receivable, net totaling approximately $14.1 million and $13.9 million, respectively.

(3)At September 30, 2024 and December 31, 2023, this amount included lease liabilities - operating leases totaling approximately $30.5 million.

(4)This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials result from impairments of investments, acquisitions through joint ventures with no change in control and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level. The Company’s basis differences include:


	September 30, 2024		December 31, 2023
Property	(in thousands)
Colorado Center	$	296,758	$	298,906
200 Fifth Avenue	51,779		58,308
Gateway Commons	51,009		48,971
Safeco Plaza	(29,032)		(29,678)
360 Park Avenue South	(114,202)		(116,534)
Dock 72	(92,930)		(95,521)
Platform 16	(142,670)		(143,052)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

(5)Investments with deficit balances aggregating approximately $30.7 million and $39.9 million at September 30, 2024 and December 31, 2023, respectively, are reflected within Other Liabilities in the Company’s Consolidated Balance Sheets.

The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows:


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Total revenue (1)	$	128,435	$	153,551	$	378,981	$	469,745
Expenses
Operating	53,280		65,119		148,929		183,348
Transaction costs	53		78		61		179
Depreciation and amortization	41,082		49,840		118,901		151,051
Total expenses	94,415		115,037		267,891		334,578
Other income (expense)
Loss from early extinguishment of debt	—		—		—		(3)
Interest expense	(45,244)		(60,737)		(132,106)		(176,786)
Unrealized gain (loss) on derivative instruments	(19,172)		10,242		(8,212)		14,089


Net loss	$	(30,396)	$	(11,981)	$	(29,228)	$	(27,533)

Company’s share of net loss	$	(9,319)	$	(4,476)	$	(9,105)	$	(10,739)

Gain on investment (2)	—		35,756		—		35,756
Gain on sale / consolidation	—		—		21,696		—
Impairment losses on investments (3)	—		(272,603)		—		(272,603)
Basis differential (4)	2,308		(6,233)		(6,215)		(14,207)
Income (loss) from unconsolidated joint ventures	$	(7,011)	$	(247,556)	$	6,376	$	(261,793)

_______________

(1)Includes straight-line rent adjustments of approximately $2.6 million and $7.7 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $16.5 million and $20.9 million for the nine months ended September 30, 2024 and 2023, respectively.

(2)During the three months ended September 30, 2023, the Company completed a restructuring of its ownership in Metropolitan Square.

(3)During the three and nine months ended September 30, 2023, the Company recognized an other-than-temporary impairment loss on its investments in Platform 16, 360 Park Avenue South, 200 Fifth Avenue and Safeco Plaza aggregating approximately $272.6 million.

(4)Includes depreciation and amortization of approximately $3.9 million and $4.1 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $6.8 million and $7.8 million for the nine months ended September 30, 2024 and 2023, respectively. Includes unrealized loss on derivative instruments of approximately $5.1 million and $2.7 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $4.9 million and $6.6 million for the nine months ended September 30, 2024 and 2023, respectively. Includes straight-line rent adjustments of approximately $0.3 million and $0.4 million for the three months ended September 30, 2024 and 2023, respectively, and approximately $1.0 million and $1.1 million for the nine months ended September 30, 2024 and 2023, respectively. Also includes net above-/below-market rent adjustments of approximately $0.2 million for the three months ended September 30, 2024 and 2023, and approximately $0.6 million for the nine months ended September 30, 2024 and 2023.

On January 2, 2024, a joint venture in which the Company has a 50% interest partially placed in-service 651 Gateway, an approximately 327,000 net rentable square foot laboratory/life sciences project in South San Francisco, California.

On January 8, 2024, the Company acquired its joint venture partner’s 50% economic ownership interest in the joint venture that owns 901 New York Avenue, located in Washington, DC, for a gross purchase price of $10.0 million in cash (See Note 3). Prior to the acquisition, the Company had a 50% economic ownership interest in the joint venture and accounted for it under the equity method of accounting. The acquisition resulted in the Company having full ownership of the joint venture such that the Company now accounts for its assets, liabilities, and operations on a consolidated basis in its financial statements instead of under the equity method of accounting. As a result, the Company recognized a gain on consolidation of approximately $21.8 million.

On February 6, 2024, a joint venture in which the Company owns a 25% interest extended the maturity date of the loan collateralized by its 3 Hudson Boulevard property. At the time of the extension, the loan had an outstanding principal balance totaling $80.0 million and was scheduled to mature on February 9, 2024. The extended loan was scheduled to mature on May 9, 2024. On May 8, 2024, the loan was extended 30 days and on June 7, 2024, the loan was extended an additional 60 days. The extended loan continued to bear interest at a variable rate equal to Term SOFR plus approximately 3.61% per annum and was scheduled to mature on August 7, 2024. As of September 30, 2024, the loan was in a maturity default and had an outstanding balance, including accrued and unpaid interest and default interest of approximately $116.0 million. The Company is the lender of the loan and the loan is reflected as Related Party Note Receivables, Net on the Company’s Consolidated Balance Sheets. 3 Hudson Boulevard consists of land and improvements held for future development located in New York, New York.

On February 9, 2024, a joint venture in which the Company owns a 50% interest exercised an option to extend the maturity date of the construction loan collateralized by its 7750 Wisconsin Avenue property. The construction loan had a total commitment amount of approximately $252.6 million. The extended loan continues to bear interest at a variable rate equal to Term SOFR plus 1.35% per annum and matures on April 26, 2025. At the time of the extension, the loan had an outstanding balance totaling approximately $251.6 million and was scheduled to mature on April 26, 2024. 7750 Wisconsin Avenue is an office property with approximately 736,000 net rentable square feet located in Bethesda, Maryland.

On July 12, 2024, a joint venture in which the Company has a 20% ownership interest partially placed in-service Skymark, a luxury residential property located in Reston, Virginia, that consists of 508 residential units aggregating approximately 417,000 net rentable square feet across a five-story low-rise building and an iconic 39-story tower, which is one of the tallest buildings in Northern Virginia.

On July 18, 2024, a joint venture in which the Company has a 50% ownership interest extended by one year the maturity date of its loan collateralized by 100 Causeway Street. At the time of the extension, the loan had an outstanding balance totaling approximately $333.6 million, bore interest at Term SOFR plus 1.48% per annum, and was scheduled to mature on September 5, 2024. Following the extension, the loan will continue to bear interest at Term SOFR plus 1.48% per annum, and is scheduled to mature on September 5, 2025. 100 Causeway Street is an approximately 634,000 net rentable square foot office property located in Boston, Massachusetts.

On August 7, 2024, a joint venture in which the Company has a 71.11% ownership interest partially placed in-service 360 Park Avenue South, a 20-story, office building with ground floor retail located in New York City, New York, aggregating approximately 450,000 net rentable square feet.

Mortgage Notes Payable, Net (Details)
$ in Thousands

Jan. 11, 2024

Jan. 08, 2024

USD ($)

ft²

Dec. 31, 2023

901 New York Avenue LLC [Member]

Debt Instrument [Line Items]

Ownership Percentage

^[1]

25.00%

901 New York Avenue

Debt Instrument [Line Items]

Net Rentable Area (in sf) | ft²

524,000

901 New York Avenue | Joint Venture Partner [Member] | 901 New York Avenue LLC [Member]

Debt Instrument [Line Items]

Ownership Percentage

50.00%

Mortgages [Member] | 901 New York Avenue

Debt Instrument [Line Items]

Debt

$ 207,100

Debt Instrument, Interest Rate, Stated Percentage

3.61%

Long-Term Debt, Fair Value

$ 198,700

Debt Instrument, Maturity Date

Jan. 05, 2025

Number of extensions

Long Term Debt, Renewal Term

[1]

$10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.

Unsecured Commercial Paper Program (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Apr. 17, 2024	Sep. 30, 2024	Dec. 31, 2023
Short-Term Debt [Line Items]
Unsecured commercial paper			$ 500,000	$ 0
Commercial Paper
Short-Term Debt [Line Items]
Commercial Paper, Maximum Borrowing Capacity		$ 500,000
Unsecured commercial paper			$ 500,000
Debt, Weighted Average Interest Rate			5.22%
Commercial Paper \| Weighted Average [Member]
Short-Term Debt [Line Items]
Debt Instrument, Term	34 days
Commercial Paper \| Maximum [Member]
Short-Term Debt [Line Items]
Debt Instrument, Term		1 year

Summary Of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2024

Summary Of Significant Accounting Policies [Line Items]

Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]

The Company follows the authoritative guidance for fair value measurements when valuing its financial instruments for disclosure purposes. The table below presents for September 30, 2024 and December 31, 2023, the financial instruments that are being valued for disclosure purposes, as well as the Level at which they are categorized as defined in Accounting Standards Codification (“ASC”) 820 “Fair Value Measurements and Disclosures” (“ASC 820”).


Financial Instrument			Level
3-Month United States Treasury Bills			Level 1
Unsecured commercial paper			Level 1
Investment in securities			Level 1
Unsecured senior notes (1)			Level 1
Related party note receivable			Level 3
Notes receivable			Level 3
Sales-type lease receivable			Level 3
Mortgage notes payable			Level 3
Unsecured line of credit			Level 3
Unsecured term loans			Level 3

_______________

(1)If trading volume for the period is low, the valuation could be categorized as Level 2.

Fair Value, by Balance Sheet Grouping [Table Text Block]

The following table presents the aggregate carrying value of the Company’s non-recurring fair value financial instruments and the Company’s corresponding estimate of fair value as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024				December 31, 2023
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
3-Month United States Treasury Bills (1)	$	175,944	$	175,944	$	302,746	$	302,746

Related party note receivable, net	$	88,788	$	90,138	$	88,779	$	90,593
Note receivable, net	3,937		4,799		1,714		1,677
Sales-type lease receivable, net	14,429		13,563		13,704		13,338
Total	$	107,154	$	108,500	$	104,197	$	105,608

Mortgage notes payable, net	$	4,275,155	$	3,907,688	$	4,166,379	$	3,705,513
Unsecured senior notes, net	10,642,033		10,191,058		10,491,617		9,697,393
Unsecured line of credit	—		—		—		—
Unsecured term loans, net	798,058		800,303		1,198,301		1,196,945
Unsecured commercial paper	500,000		500,000		—		—
Total	$	16,215,246	$	15,399,049	$	15,856,297	$	14,599,851

_______________

(1) Per the guidance in ASC 326 “Financial Instruments — Credit Losses” (“ASC 326”), the Company concluded that the risk of nonpayment is nonexistent because the U.S. Government has a long history with no credit losses and, therefore, no credit loss allowance was recorded.

Schedule of Derivative Assets at Fair Value [Table Text Block]

The following table presents the aggregate fair value of the Company’s interest rate swaps as of September 30, 2024 and December 31, 2023 (in thousands):


Fair value	September 30, 2024		December 31, 2023
Interest rate swaps	$	(10,191)	$	1,976

Summary Of Significant Accounting Policies Fair Value of Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Cash Flow Hedges Derivative Instruments at Fair Value, Net	$ (10,191)	$ 1,976

Real Estate Schedule of Real Estate Properties (Details) - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

Real Estate Properties [Line Items]

Land

$ 5,318,724

$ 5,251,224

Right-of-use assets - finance leases

^[1]

372,896

401,680

Operating Lease, Right-of-Use Asset

^[1]

339,804

324,298

Land held for future development

^[2]

690,774

697,061

Buildings and improvements

16,898,821

16,607,756

Tenant improvements

3,782,391

3,592,172

Furniture, Fixtures and Equipment

54,992

53,716

Construction in progress

812,122

547,280

Total

28,270,524

27,475,187

Less: accumulated depreciation

(7,369,545)

(6,881,728)

Total real estate

20,900,979

20,593,459

Boston Properties Limited Partnership

Real Estate Properties [Line Items]

Land

5,224,015

5,156,515

Right-of-use assets - finance leases

^[1]

372,896

401,680

Operating Lease, Right-of-Use Asset

^[1]

339,804

324,298

Land held for future development

^[2]

690,774

697,061

Buildings and improvements

16,627,265

16,336,200

Tenant improvements

3,782,391

3,592,172

Furniture, Fixtures and Equipment

54,992

53,716

Construction in progress

812,122

547,280

Total

27,904,259

27,108,922

Less: accumulated depreciation

(7,241,074)

(6,758,361)

Total real estate

$ 20,663,185

$ 20,350,561

[1]	See Note 4.
[2]	Includes pre-development costs.

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net income (loss)	$ 322,005	$ 138,269
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	661,148	618,746
Impairment loss	13,615	0
Amortization of right of use assets - operating leases	1,719	1,502
Amortization of sales type lease	(738)	0
Amortization of above and below Market Leases	(4,245)	0
Non-cash compensation expense	39,552	46,699
Loss (income) from unconsolidated joint ventures	(6,376)	261,793
Distributions of net cash flow from operations of unconsolidated joint ventures	27,332	21,871
Gains from investments in securities	(4,785)	(2,311)
Allowance for current expected credit losses	44	302
Non-cash portion of interest expense	25,575	22,541
Gains on sales of real estate	(517)	(517)
Unrealized (Gain) Loss on non-real estate Investments	(548)	(332)
Change in assets and liabilities:
Tenant and other receivables, net	23,932	(13,467)
Accrued rental income, net	(78,576)	(72,190)
Prepaid expenses and other assets	(73,215)	(76,621)
Right of use assets - operating lease	(750)	(25,640)
Lease liabilities - operating leases	(390)	282
Accounts payable and accrued expenses	7,596	40,914
Accrued interest payable	(12,383)	24,648
Other liabilities	(27,579)	(6,254)
Tenant leasing costs	(61,661)	(65,863)
Total adjustments	528,750	776,103
Net cash provided by operating activities	850,755	914,372
Cash flows from investing activities:
Construction in progress	(469,948)	(361,625)
Building and other capital improvements	(118,411)	(117,393)
Tenant improvements	(178,835)	(244,841)
Proceeds from sales of real estate	517	517
Acquisition of real estate (net of cash received upon consolidation)	6,086	0
Capital contributions to unconsolidated joint ventures	(87,498)	(148,875)
Capital distributions from unconsolidated joint ventures	0	7,350
Investment in non-real estate investments	(1,500)	(1,990)
Issuance of note receivables (including related party)	(2,223)	(10,500)
Investments in securities, net	1,025	1,779
Net cash used in investing activities	(850,787)	(875,578)
Cash flows from financing activities:
Repayments of mortgage notes payable	(3,461)	0
Proceeds from unsecured senior notes	849,671	747,727
Redemption of unsecured senior notes	(700,000)	(500,000)
Borrowings on unsecured term loans	0	1,200,000
Payments on finance lease obligations	(9,250)	0
Repayment of unsecured term loan	(500,000)	(730,000)
Proceeds from Issuance of Commercial Paper	3,554,932	0
Repayments of Commercial Paper	(3,054,932)	0
Deferred financing costs	(10,892)	(12,639)
Net activity from equity transactions	(1,728)	367
Dividends and distributions	(517,361)	(514,974)
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	306,147	30,190
Distributions to noncontrolling interests in property partnerships	(52,353)	(48,370)
Net cash provided by (used in) financing activities	(141,051)	154,782
Net increase (decrease) in cash and cash equivalents and cash held in escrows	(141,083)	193,576
Cash and cash equivalents and cash held in escrows, beginning of period	1,612,567	736,812
Cash and cash equivalents and cash held in escrows, end of period	1,471,484	930,388
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	1,531,477	690,333
Cash held in escrows, beginning of period	81,090	46,479
Cash and cash equivalents, end of period	1,420,475	882,647
Cash held in escrows,end of period	51,009	47,741
Supplemental disclosures:
Cash paid for interest	505,746	404,016
Interest capitalized	31,342	33,426
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(76,653)	(111,154)
Change in real estate included in accounts payable and accrued expenses	(21,035)	29,435
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	30,631	134,509
Finance Lease, Liability, Reversal from Re-Assessment	(38,491)	0
Finance Lease, Right-of-Use Asset, Reversal from Re-Assessment	(28,962)	0
Non-cash contributions from noncontrolling interest in property partnerhips	86,860	17,519
Capitalized operating lease costs	22,647	5,031
Construction in progress from prepaid expenses and other assets	0	25,577
Investment in unconsolidated joint ventures eliminated upon consolidation	(11,834)	0
Mortgage notes payable recorded upon consolidation	207,093	0
Real estate and intangibles recorded upon consolidation	(220,015)	0
Dividends and distributions declared but not paid	172,191	171,916
Conversions of noncontrolling interests to stockholders’ equity	33,746	3,714
Issuance of restricted securities to employees and non-employee directors	43,360	48,121
Mortgage note payable converted to unsecured term loan	100,000	0
Cash
Cash flows from financing activities:
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	304,323	12,671
Boston Properties Limited Partnership
Net income (loss)	327,109	143,569
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	656,044	613,446
Impairment loss	13,615	0
Amortization of right of use assets - operating leases	1,719	1,502
Amortization of sales type lease	(738)	0
Amortization of above and below Market Leases	(4,245)	0
Non-cash compensation expense	39,552	46,699
Loss (income) from unconsolidated joint ventures	(6,376)	261,793
Distributions of net cash flow from operations of unconsolidated joint ventures	27,332	21,871
Gains from investments in securities	(4,785)	(2,311)
Allowance for current expected credit losses	44	302
Non-cash portion of interest expense	25,575	22,541
Gains on sales of real estate	(517)	(517)
Unrealized (Gain) Loss on non-real estate Investments	(548)	(332)
Change in assets and liabilities:
Tenant and other receivables, net	23,932	(13,467)
Accrued rental income, net	(78,576)	(72,190)
Prepaid expenses and other assets	(73,215)	(76,621)
Right of use assets - operating lease	(750)	(25,640)
Lease liabilities - operating leases	(390)	282
Accounts payable and accrued expenses	7,596	40,914
Accrued interest payable	(12,383)	24,648
Other liabilities	(27,579)	(6,254)
Tenant leasing costs	(61,661)	(65,863)
Total adjustments	523,646	770,803
Net cash provided by operating activities	850,755	914,372
Cash flows from investing activities:
Construction in progress	(469,948)	(361,625)
Building and other capital improvements	(118,411)	(117,393)
Tenant improvements	(178,835)	(244,841)
Proceeds from sales of real estate	517	517
Acquisition of real estate (net of cash received upon consolidation)	6,086	0
Capital contributions to unconsolidated joint ventures	(87,498)	(148,875)
Capital distributions from unconsolidated joint ventures	0	7,350
Investment in non-real estate investments	(1,500)	(1,990)
Issuance of note receivables (including related party)	(2,223)	(10,500)
Investments in securities, net	1,025	1,779
Net cash used in investing activities	(850,787)	(875,578)
Cash flows from financing activities:
Repayments of mortgage notes payable	(3,461)	0
Proceeds from unsecured senior notes	849,671	747,727
Redemption of unsecured senior notes	(700,000)	(500,000)
Borrowings on unsecured term loans	0	1,200,000
Payments on finance lease obligations	9,250	0
Repayment of unsecured term loan	(500,000)	(730,000)
Proceeds from Issuance of Commercial Paper	3,554,932	0
Repayments of Commercial Paper	(3,054,932)	0
Deferred financing costs	(10,892)	(12,639)
Net activity from equity transactions	(1,728)	367
Dividends and distributions	(517,361)	(514,974)
Distributions to noncontrolling interests in property partnerships	(52,353)	(48,370)
Net cash provided by (used in) financing activities	(141,051)	154,782
Net increase (decrease) in cash and cash equivalents and cash held in escrows	(141,083)	193,576
Cash and cash equivalents and cash held in escrows, beginning of period	1,612,567	736,812
Cash and cash equivalents and cash held in escrows, end of period	1,471,484	930,388
Reconciliation of cash and cash equivalents and cash held in escrow
Cash and cash equivalents, beginning of period	1,531,477	690,333
Cash held in escrows, beginning of period	81,090	46,479
Cash and cash equivalents, end of period	1,420,475	882,647
Cash held in escrows,end of period	51,009	47,741
Supplemental disclosures:
Cash paid for interest	505,746	404,016
Interest capitalized	31,342	33,426
Non-cash investing and financing activities:
Write-off of fully depreciated real estate	(76,653)	(109,905)
Change in real estate included in accounts payable and accrued expenses	(21,035)	29,435
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	30,631
Finance Lease, Liability, Reversal from Re-Assessment	(38,491)	0
Finance Lease, Right-of-Use Asset, Reversal from Re-Assessment	(28,962)	0
Non-cash contributions from noncontrolling interest in property partnerhips	86,860	17,519
Capitalized operating lease costs	22,647	5,031
Construction in progress from prepaid expenses and other assets	0	25,577
Investment in unconsolidated joint ventures eliminated upon consolidation	(11,834)	0
Mortgage notes payable recorded upon consolidation	207,093	0
Real estate and intangibles recorded upon consolidation	(220,015)	0
Dividends and distributions declared but not paid	172,191	171,916
Conversions of noncontrolling interests to stockholders’ equity	33,746	3,714
Issuance of restricted securities to employees and non-employee directors	43,360	48,121
Mortgage note payable converted to unsecured term loan	100,000	0
Boston Properties Limited Partnership \| Cash
Cash flows from financing activities:
Proceeds from sale of interest in property partnerships and contributions from noncontrolling interests in property partnerships	$ 304,323	$ 12,671

Stock Option and Incentive Plan Stock and Units (Narrative) (Details)
$ / shares in Units, $ in Thousands

3 Months Ended

9 Months Ended

Feb. 01, 2024

USD ($)

Jan. 25, 2024

USD ($)

Sep. 30, 2024

USD ($)

Sep. 30, 2023

USD ($)

Sep. 30, 2024

USD ($)

$ / shares

Sep. 30, 2023

USD ($)

Dec. 31, 2023

USD ($)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares issued

158,058,798

157,019,766

Stock based compensation expense | $

$ 4,000

$ 4,800

$ 38,500

$ 45,700

Common Stock, Value, Issued | $

$ 1,580

$ 1,569

Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares issued

83,316

LTIP Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Value Of LTIP Units Issued | $

$ 26,700

MYLTIP 2024

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Value of MYLTIP Awards | $

$ 11,100

MYLTIP 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Final awards percentage of target

112.00%

Value of MYLTIP Awards | $

$ 12,600

Forfeitures, in units

155,625

Unvested Restricted stock and LTIP Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Annual Installments for Vesting

Boston Properties Limited Partnership | LTIP Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares issued

451,044

Noncontrolling Interest, Outstanding

^[1]

2,336,797

Boston Properties Limited Partnership | MYLTIP 2024

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Noncontrolling Interest, Outstanding

330,479

Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award

The 2024 MYLTIP awards consists of three components. Two of the components, each weighted 40%, utilize BXP’s TSR over a three-year measurement period as the performance metrics and the third component utilizes a leverage ratio as the performance metric.

Boston Properties Limited Partnership | MYLTIP 2024 | Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock available for issuance

330,479

Boston Properties Limited Partnership | MYLTIP 2024 | Minimum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock available for issuance

Boston Properties Limited Partnership | MYLTIP 2024 | Target

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Common stock available for issuance

165,240

Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Employee and director payment per share (in dollars per share) | $ / shares

$ 0.01

Common Stock, Value, Issued | $

$ 5,300

Ltips (including vested MYLTIPS) And Restricted Stock [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation expenses | $

25,400

Unvested MYLTIP Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation expenses | $

$ (40)

Weighted-average period (years)

2 years 6 months

LTIP and MYLTIP Units [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Employee and director payment per share (in dollars per share) | $ / shares

$ 0.25

[1]	Includes 617,961 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2021 (i.e., 2012 OPP and 2013 - 2021 MYLTIP awards).

Commitments And Contingencies (Details) $ in Thousands	9 Months Ended
Commitments And Contingencies (Details) $ in Thousands	Sep. 30, 2024 USD ($) ft² Real_Estate_Properties	Dec. 31, 2023 USD ($)	Oct. 02, 2023 USD ($) ft²	Jan. 05, 2023 ft²
Commitments And Contingencies [Line Items]
Letter of credit and performance obligations	$ 21,000
Note receivable, net	3,937	$ 1,714
Accrued Liabilities	1,500
Loss Contingency, Portion Not Accrued	31,000
Property insurance program per occurrence limits	1,000,000
Per occurrence limit for NBCR Coverage	1,000,000
Value of program trigger	$ 200,000
Coinsurance of program trigger	20.00%
Program trigger deductible	20.00%
Per occurrence limit of the earthquake insurance which covers San Francisco and Los Angeles regions	$ 330,000
Annual aggregate limit of the earthquake insurance which covers San Francisco and Los Angeles regions	330,000
Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco and Los Angeles	$ 30,000
Deductible in insurance as a percentage of the value of the affected property, San Francisco and Los Angeles	5.00%
Per Occurrence Limit of Earthquake Insurance Seattle	$ 110,000
Annual Aggregate Limit of Earthquake Insurance Seattle	$ 110,000
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle	2.00%
Construction in Progress
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²	2,700,000
Number of real estate properties \| Real_Estate_Properties	9
Boston Properties Limited Partnership
Commitments And Contingencies [Line Items]
Note receivable, net	$ 3,937	$ 1,714
Operating partnership guarantee to cover liabilities of IXP	20,000
767 Venture, LLC [Member]
Commitments And Contingencies [Line Items]
Maximum funding obligation	6,400
Property insurance program per occurrence limits	1,625,000
Metropolitan Square
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²			657,000
Debt Instrument, Unused Borrowing Capacity, Amount			$ 100,000
Debt Instrument, Interest Rate, Stated Percentage			12.00%
Metropolitan Square \| Affiliated Entity
Commitments And Contingencies [Line Items]
Note receivable, net	3,900
Metropolitan Square \| Scenario, Plan \| Affiliated Entity
Commitments And Contingencies [Line Items]
Loans and Leases Receivable, Loans in Process			$ 20,000
Metropolitan Square \| Metropolitan Square
Commitments And Contingencies [Line Items]
Ownership Percentage			20.00%
601 Lexington Avenue
Commitments And Contingencies [Line Items]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP	1,350,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism	750,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism	600,000
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism	$ 1,750,000
Office and Life Sciences Building [Member]
Commitments And Contingencies [Line Items]
Number of real estate properties \| Real_Estate_Properties	162
Office and Life Sciences Building [Member] \| Construction in Progress
Commitments And Contingencies [Line Items]
Number of real estate properties \| Real_Estate_Properties	6
Office and Life Sciences Building [Member] \| 290 Binney \| Construction in Progress
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²	573,000			573,000
Consolidated Entities, Ownership Percentage	55.00%
Leased percentage	100.00%			100.00%
Office and Life Sciences Building [Member] \| 250 Binney Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) \| ft²	67,000

Segment Information (Schedule Of Reconciliation Of Net Operating Income To Net Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company	$ 83,628	$ (111,826)	$ 243,126	$ 70,290
Noncontrolling interest-common units of the Operating Partnership	(9,587)	12,626	(28,596)	(8,642)
Noncontrolling interest in property partnerships	(15,237)	(20,909)	(50,283)	(59,337)
Interest expense	(163,194)	(147,812)	(474,727)	(424,492)
Gain (Loss) from interest rate contracts	0	0	0	0
Company's share of net operating income from joint ventures	(511,078)	(501,881)	(1,528,615)	(1,496,376)
Depreciation and amortization expense	(222,890)	(207,435)	(661,148)	(618,746)
Transaction costs	(188)	(751)	(890)	(1,970)
General and administrative expense	(33,352)	(31,410)	(127,479)	(131,387)
Unrealized gain (loss) on non-real estate investments	(94)	51	(548)	(332)
Gains (losses) from investments in securities	(2,198)	925	(4,785)	(2,311)
Interest and other income (loss)	(14,430)	(20,715)	(39,747)	(48,999)
Gains on sales of real estate	(517)	(517)	(517)	(517)
Income (loss) from unconsolidated joint ventures	7,011	247,556	(6,376)	261,793
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company	83,628	(111,826)	243,126	70,290
Noncontrolling interest-common units of the Operating Partnership	9,587	(12,626)	28,596	8,642
Noncontrolling interest in property partnerships	15,237	20,909	50,283	59,337
Interest expense	163,194	147,812	474,727	424,492
Impairment loss	0	0	13,615	0
Depreciation and amortization expense	222,890	207,435	661,148	618,746
Transaction costs	188	751	890	1,970
Operating expense	3,649	3,906	12,090	13,750
General and administrative expense	33,352	31,410	127,479	131,387
Unrealized gain (loss) on non-real estate investments	94	(51)	548	332
Gains (losses) from investments in securities	2,198	(925)	4,785	2,311
Interest and other income (loss)	14,430	20,715	39,747	48,999
Gains on sales of real estate	517	517	517	517
Income (loss) from unconsolidated joint ventures	(7,011)	(247,556)	6,376	(261,793)
Other revenue	3,649	3,906	12,090	13,750
Company's share of Net Operating Income	498,510	490,999	1,489,103	1,473,449
Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company	94,919	(122,696)	276,826	84,232
Noncontrolling interest in property partnerships	(15,237)	(20,909)	(50,283)	(59,337)
Interest expense	(163,194)	(147,812)	(474,727)	(424,492)
Depreciation and amortization expense	(221,186)	(205,679)	(656,044)	(613,446)
Transaction costs	(188)	(751)	(890)	(1,970)
General and administrative expense	(33,352)	(31,410)	(127,479)	(131,387)
Unrealized gain (loss) on non-real estate investments	(94)	51	(548)	(332)
Gains (losses) from investments in securities	(2,198)	925	(4,785)	(2,311)
Interest and other income (loss)	(14,430)	(20,715)	(39,747)	(48,999)
Gains on sales of real estate	(517)	(517)	(517)	(517)
Income (loss) from unconsolidated joint ventures	7,011	247,556	(6,376)	261,793
Boston Properties Limited Partnership \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income attributable to the Company	94,919	(122,696)	276,826	84,232
Noncontrolling interest in property partnerships	15,237	20,909	50,283	59,337
Interest expense	163,194	147,812	474,727	424,492
Impairment loss	0	0	13,615	0
Depreciation and amortization expense	221,186	205,679	656,044	613,446
Transaction costs	188	751	890	1,970
Operating expense	3,649	3,906	12,090	13,750
General and administrative expense	33,352	31,410	127,479	131,387
Unrealized gain (loss) on non-real estate investments	94	(51)	548	332
Gains (losses) from investments in securities	2,198	(925)	4,785	2,311
Interest and other income (loss)	14,430	20,715	39,747	48,999
Gains on sales of real estate	517	517	517	517
Income (loss) from unconsolidated joint ventures	(7,011)	(247,556)	6,376	(261,793)
Other revenue	3,649	3,906	12,090	13,750
Company's share of Net Operating Income	498,510	490,999	1,489,103	1,473,449
Unconsolidated Joint Ventures [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest expense	(45,244)	(60,737)	(132,106)	(176,786)
Losses from early extinguishment of debt	0	0	0	3
Company's share of net operating income from joint ventures	(31,919)	(39,165)	(98,936)	(122,175)
Depreciation and amortization expense	(41,082)	(49,840)	(118,901)	(151,051)
Transaction costs	(53)	(78)	(61)	(179)
Income (loss) from unconsolidated joint ventures	7,011	247,556	(6,376)	261,793
Unconsolidated Joint Ventures [Member] \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	31,919	39,165	98,936	122,175
Management Service [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(6,770)	(9,284)	(19,276)	(28,122)
Management Service [Member] \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	6,770	9,284	19,276	28,122
Management Service [Member] \| Boston Properties Limited Partnership
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	(6,770)	(9,284)	(19,276)	(28,122)
Management Service [Member] \| Boston Properties Limited Partnership \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other revenue	6,770	9,284	19,276	28,122
Noncontrolling interest - property partnerships [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	44,487	50,047	138,448	145,102
Noncontrolling interest - property partnerships [Member] \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	44,487	50,047	138,448	145,102
Noncontrolling interest - property partnerships [Member] \| Boston Properties Limited Partnership \| Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Company's share of net operating income from joint ventures	$ 44,487	$ 50,047	$ 138,448	$ 145,102

Summary Of Significant Accounting Policies (Policies)	9 Months Ended
Summary Of Significant Accounting Policies (Policies)	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income. The accompanying interim financial statements are unaudited; however, the financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and in conjunction with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting solely of normal recurring matters) necessary for a fair statement of the financial statements for these interim periods have been included. The results of operations for the interim periods are not necessarily indicative of the results to be obtained for other interim periods or for the full fiscal year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosure required by GAAP. These financial statements should be read in conjunction with the Company’s financial statements and notes thereto contained in the Company’s Annual Report in the Company’s Form 10-K for its fiscal year ended December 31, 2023.
Use of Estimates in the Preparation of Financial Statements	The Company bases its estimates on historical experience and on various other assumptions that it considers to be reasonable under the circumstances, including the impact of extraordinary events, the results of which form the basis for making significant judgments about the carrying values of assets and liabilities, assessments of future collectability, and other areas of the financial statements that are impacted by the use of estimates. Actual results may differ from these estimates under different assumptions or conditions.
Consolidation, Variable Interest Entity, Policy	Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE. The assets of each VIE are only available to satisfy such VIE's respective liabilities.
Derivative Instruments and Hedging Activities	In addition to the financial instruments noted above, the Company uses interest rate swap agreements to manage its interest rate risk (See Note 7). The valuation of these instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. To comply with the provisions of ASC 820, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. The Company assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and determined that the credit valuation adjustments were not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.

Subsequent Events (Details) $ in Thousands		9 Months Ended
Subsequent Events (Details) $ in Thousands	Oct. 08, 2024 USD ($) ft² buildings	Jul. 19, 2025	Oct. 31, 2024 ft²	Oct. 05, 2024 ft²	Sep. 27, 2024 USD ($)
Santa Monica Business Park [Member]
Subsequent Event [Line Items]
Debt \| $					$ 200,000
Subsequent Event [Member] \| 103 CityPoint
Subsequent Event [Line Items]
Net Rentable Area (in sf)				113,000
Subsequent Event [Member] \| Santa Monica Business Park [Member]
Subsequent Event [Line Items]
Net Rentable Area (in sf)	1,200,000
Debt \| $	$ 200,000
Debt Instrument, Basis Spread on Variable Rate	1.38%	1.38%
Number of buildings \| buildings	21
Derivative, Average Fixed Interest Rate	2.675%
Subsequent Event [Member] \| Santa Monica Business Park [Member] \| Forecast
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.60%
Subsequent Event [Member] \| Santa Monica Business Park [Member] \| Extended Maturity
Subsequent Event [Line Items]
Debt Instrument, Maturity Date	Oct. 08, 2028
Subsequent Event [Member] \| 300 Binney Street
Subsequent Event [Line Items]
Net Rentable Area (in sf)			236,000

Segment Information

9 Months Ended

Sep. 30, 2024

Segment Reporting [Abstract]

Segment Reporting Disclosure [Text Block]

11. Segment Information

The following tables present reconciliations of Net Income (Loss) Attributable to BXP, Inc. to the Company’s share of Net Operating Income and Net Income (Loss) Attributable to Boston Properties Limited Partnership to the Company’s share of Net Operating Income for the three and nine months ended September 30, 2024 and 2023.

BXP


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Net income (loss) attributable to BXP, Inc.	$	83,628	$	(111,826)	$	243,126	$	70,290
Add:
Noncontrolling interest—common units of the Operating Partnership	9,587		(12,626)		28,596		8,642
Noncontrolling interests in property partnerships	15,237		20,909		50,283		59,337
Interest expense	163,194		147,812		474,727		424,492
Impairment loss	—		—		13,615		—


Net operating income from unconsolidated joint ventures	31,919		39,165		98,936		122,175
Depreciation and amortization expense	222,890		207,435		661,148		618,746
Transaction costs	188		751		890		1,970
Payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
General and administrative expense	33,352		31,410		127,479		131,387
Less:
Net operating income attributable to noncontrolling interests in property partnerships	44,487		50,047		138,448		145,102
Unrealized gain (loss) on non-real estate investment	94		(51)		548		332
Gains (losses) from investments in securities	2,198		(925)		4,785		2,311

Interest and other income (loss)	14,430		20,715		39,747		48,999
Gains on sales of real estate	517		517		517		517
Income (loss) from unconsolidated joint ventures	(7,011)		(247,556)		6,376		(261,793)

Direct reimbursements of payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
Development and management services revenue	6,770		9,284		19,276		28,122
Company’s share of Net Operating Income	$	498,510	$	490,999	$	1,489,103	$	1,473,449

BPLP


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Net income (loss) attributable to Boston Properties Limited Partnership	$	94,919	$	(122,696)	$	276,826	$	84,232
Add:
Noncontrolling interests in property partnerships	15,237		20,909		50,283		59,337
Interest expense	163,194		147,812		474,727		424,492


Impairment loss	—		—		13,615		—
Net operating income from unconsolidated joint ventures	31,919		39,165		98,936		122,175
Depreciation and amortization expense	221,186		205,679		656,044		613,446
Transaction costs	188		751		890		1,970
Payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
General and administrative expense	33,352		31,410		127,479		131,387
Less:
Net operating income attributable to noncontrolling interests in property partnerships	44,487		50,047		138,448		145,102
Unrealized gain (loss) on non-real estate investment	94		(51)		548		332
Gains (losses) from investments in securities	2,198		(925)		4,785		2,311

Interest and other income (loss)	14,430		20,715		39,747		48,999
Gains on sales of real estate	517		517		517		517
Income (loss) from unconsolidated joint ventures	(7,011)		(247,556)		6,376		(261,793)

Direct reimbursements of payroll and related costs from management services contracts	3,649		3,906		12,090		13,750
Development and management services revenue	6,770		9,284		19,276		28,122
Company’s share of Net Operating Income	$	498,510	$	490,999	$	1,489,103	$	1,473,449

Net operating income (“NOI”) is a non-GAAP financial measure equal to net income (loss) attributable to BXP, Inc. and net income (loss) attributable to Boston Properties Limited Partnership, as applicable, the most directly comparable GAAP financial measures, plus (1) net income (loss) attributable to noncontrolling interests, interest expense, impairment loss, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts and corporate general and administrative expense less (2) unrealized gain (loss) on non-real estate investment, gains (losses) from investments in securities, interest and other income (loss), gains on sales of real estate, income (loss) from unconsolidated joint ventures, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue. The Company believes NOI is useful to investors as a performance measure and believes it provides useful information to investors regarding its results of operations and financial condition because, when compared across periods, it reflects the impact on operations from trends in occupancy rates, rental rates, operating costs and acquisition and development activity on an unleveraged basis, providing perspective not immediately apparent from net income (loss) attributable to BXP, Inc. and net income (loss) attributable to Boston Properties Limited Partnership. For example, interest expense is not necessarily linked to the operating performance of a real estate asset and is often incurred at the corporate level as opposed to the property level. Similarly, interest expense may be incurred at the property level even though the financing proceeds may be used at the corporate level (e.g., used for other investment activity). In addition, depreciation and amortization expense, because of historical cost accounting and useful life estimates, may distort operating performance measures at the property level. NOI presented by the Company may not be comparable to NOI reported by other REITs or real estate companies that define NOI differently.

The Company’s internal reporting utilizes its share of NOI, which includes its share of NOI from consolidated and unconsolidated joint ventures, which is a non-GAAP financial measure that is calculated as the consolidated amount, plus the Company’s share of the amount from the Company’s unconsolidated joint ventures (calculated based upon the Company’s economic percentage ownership interest and, in some cases, after priority allocations), less the Company’s partners’ share of the amount from the Company’s consolidated joint ventures (calculated based upon the partners’ economic percentage ownership interests and, in some cases, after priority allocations, income allocation to private REIT shareholders and their share of fees due to the Company). The Company’s share of NOI from unconsolidated joint ventures, as defined above, also does not include its share of loss from early extinguishment of debt, unrealized gain (loss) on derivative instruments, gain on sale / consolidation, gain on investment, and impairment losses on investments, all of which are included within Income (Loss) from Unconsolidated Joint Ventures in the Company’s Consolidated Statements of Operations. Management utilizes its share of NOI in assessing its performance as the Company has several significant joint ventures and, in some cases, the Company exercises significant influence over, but does not control, the joint venture, in which case GAAP requires that the Company account for the joint venture entity using the equity method of accounting and the Company does not consolidate it for financial reporting purposes. In other cases, GAAP requires that the Company consolidate the venture even though the Company’s partner(s) owns a significant percentage interest. As a result, the presentations of the Company’s share of NOI should not be considered a substitute for, and should only be considered together with and as a supplement to, the Company’s financial information presented in accordance with GAAP.

Asset information by segment is not reported because the Company does not use this measure to assess performance. Therefore, depreciation and amortization expense is not allocated among segments. Interest expense, impairment loss, depreciation and amortization expense, transaction costs, payroll and related costs from management services contracts, corporate general and administrative expense, unrealized gain (loss) on non-real estate investment, gains (losses) from investments in securities, interest and other income (loss), gains on sales of real estate, income (loss) from unconsolidated joint ventures, direct reimbursements of payroll and related costs from management services contracts and development and management services revenue are not included in NOI and are provided as reconciling items to the Company’s reconciliations of its share of NOI to net income.

The Company’s segments are based on the Company’s method of internal reporting which classifies its operations by geographic area. The Company’s segments by geographic area are Boston, Los Angeles, New York, San Francisco, Seattle and Washington, DC. The Company also presents information for each segment by property type, including Office (which includes office, life sciences and retail), Residential and Hotel.

Information by geographic area and property type (dollars in thousands):

For the three months ended September 30, 2024:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	300,613		$	18,661		$	258,295		$	128,929		$	10,821		$	104,290		$	821,609
Residential	4,219			—			—			3,152			—			4,746			12,117
Hotel	15,082			—			—			—			—			—			15,082
Total	319,914			18,661			258,295			132,081			10,821			109,036			848,808
% of Grand Totals	37.69		%	2.20		%	30.43		%	15.56		%	1.27		%	12.85		%	100.00		%
Rental Expenses:
Office	107,876			7,344			111,419			52,410			3,382			39,478			321,909
Residential	1,621			—			—			2,346			—			2,021			5,988
Hotel	9,833			—			—			—			—			—			9,833
Total	119,330			7,344			111,419			54,756			3,382			41,499			337,730
% of Grand Totals	35.34		%	2.17		%	32.99		%	16.21		%	1.00		%	12.29		%	100.00		%
Net operating income	$	200,584		$	11,317		$	146,876		$	77,325		$	7,439		$	67,537		$	511,078
% of Grand Totals	39.25		%	2.21		%	28.74		%	15.13		%	1.46		%	13.21		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(10,823)			—			(33,664)			—			—			—			(44,487)
Add: Company’s share of net operating income from unconsolidated joint ventures	9,099			6,835			3,472			4,285			1,899			6,329			31,919
Company’s share of net operating income	$	198,860		$	18,152		$	116,684		$	81,610		$	9,338		$	73,866		$	498,510
% of Grand Totals	39.89		%	3.64		%	23.41		%	16.37		%	1.87		%	14.82		%	100.00		%

_______________

For the three months ended September 30, 2023:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	276,153		$	—		$	268,680		$	135,839		$	13,660		$	91,488		$	785,820
Residential	4,198			—			—			3,214			—			4,377			11,789
Hotel	13,484			—			—			—			—			—			13,484
Total	293,835			—			268,680			139,053			13,660			95,865			811,093
% of Grand Totals	36.23		%	—		%	33.13		%	17.14		%	1.68		%	11.82		%	100.00		%
Rental Expenses:
Office	97,358			—			107,462			50,450			2,971			36,213			294,454
Residential	1,629			—			—			2,221			—			1,888			5,738
Hotel	9,020			—			—			—			—			—			9,020
Total	108,007			—			107,462			52,671			2,971			38,101			309,212
% of Grand Totals	34.94		%	—		%	34.75		%	17.03		%	0.96		%	12.32		%	100.00		%
Net operating income	$	185,828		$	—		$	161,218		$	86,382		$	10,689		$	57,764		$	501,881
% of Grand Totals	37.03		%	—		%	32.12		%	17.21		%	2.13		%	11.51		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(11,786)			—			(38,261)			—			—			—			(50,047)
Add: Company’s share of net operating income from unconsolidated joint ventures	7,946			12,508			3,938			4,023			1,874			8,876			39,165
Company’s share of net operating income	$	181,988		$	12,508		$	126,895		$	90,405		$	12,563		$	66,640		$	490,999
% of Grand Totals	37.07		%	2.55		%	25.84		%	18.41		%	2.56		%	13.57		%	100.00		%

_______________

For the nine months ended September 30, 2024:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	866,431		$	57,534		$	780,909		$	393,252		$	32,251		$	312,298		$	2,442,675
Residential	12,687			—			—			10,428			—			13,912			37,027
Hotel	38,080			—			—			—			—			—			38,080
Total	917,198			57,534			780,909			403,680			32,251			326,210			2,517,782
% of Grand Totals	36.42		%	2.29		%	31.02		%	16.03		%	1.28		%	12.96		%	100.00		%
Rental Expenses:
Office	321,955			20,678			327,376			148,020			9,753			118,285			946,067
Residential	4,757			—			—			6,733			—			5,923			17,413
Hotel	25,687			—			—			—			—			—			25,687
Total	352,399			20,678			327,376			154,753			9,753			124,208			989,167
% of Grand Totals	35.62		%	2.09		%	33.10		%	15.64		%	0.99		%	12.56		%	100.00		%
Net operating income	$	564,799		$	36,856		$	453,533		$	248,927		$	22,498		$	202,002		$	1,528,615
% of Grand Totals	36.96		%	2.41		%	29.67		%	16.28		%	1.47		%	13.21		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(32,803)			—			(105,645)			—			—			—			(138,448)
Add: Company’s share of net operating income from unconsolidated joint ventures	26,547			21,118			12,614			13,850			5,713			19,094			98,936
Company’s share of net operating income	$	558,543		$	57,974		$	360,502		$	262,777		$	28,211		$	221,096		$	1,489,103
% of Grand Totals	37.51		%	3.89		%	24.21		%	17.65		%	1.89		%	14.85		%	100.00		%

_______________

For the nine months ended September 30, 2023:


	Boston			Los Angeles			New York			San Francisco			Seattle			Washington, DC			Total
Rental Revenue: (1)
Office	$	815,568		$	—		$	789,851		$	408,173		$	44,978		$	272,872		$	2,331,442
Residential	12,371			—			—			10,720			—			12,677			35,768
Hotel	35,554			—			—			—			—			—			35,554
Total	863,493			—			789,851			418,893			44,978			285,549			2,402,764
% of Grand Totals	35.95		%	—		%	32.87		%	17.43		%	1.87		%	11.88		%	100.00		%
Rental Expenses:
Office	293,004			—			312,895			144,732			9,013			105,908			865,552
Residential	4,782			—			—			6,609			—			5,593			16,984
Hotel	23,852			—			—			—			—			—			23,852
Total	321,638			—			312,895			151,341			9,013			111,501			906,388
% of Grand Totals	35.49		%	—		%	34.52		%	16.70		%	0.99		%	12.30		%	100.00		%
Net operating income	$	541,855		$	—		$	476,956		$	267,552		$	35,965		$	174,048		$	1,496,376
% of Grand Totals	36.22		%	—		%	31.87		%	17.88		%	2.40		%	11.63		%	100.00		%
Less: Net operating income attributable to noncontrolling interests in property partnerships	(33,946)			—			(111,156)			—			—			—			(145,102)
Add: Company’s share of net operating income from unconsolidated joint ventures	25,294			38,501			10,951			10,819			5,598			31,012			122,175
Company’s share of net operating income	$	533,203		$	38,501		$	376,751		$	278,371		$	41,563		$	205,060		$	1,473,449
% of Grand Totals	36.19		%	2.61		%	25.57		%	18.89		%	2.82		%	13.92		%	100.00		%

_______________

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

Investments in Unconsolidated Joint Ventures (Tables)

9 Months Ended

Sep. 30, 2024

Schedule of Equity Method Investments [Line Items]

Investments In Unconsolidated Joint Ventures

The investments in unconsolidated joint ventures consist of the following at September 30, 2024 and December 31, 2023:


					Carrying Value of Investment (1)
Entity	Properties	Nominal % Ownership			September 30, 2024		December 31, 2023
					(in thousands)
Square 407 Limited Partnership	Market Square North	50.00	%		$	(12,042)	$	(5,996)
901 New York, LLC	901 New York Avenue	25.00	%	(2)	—		(11,764)
WP Project Developer LLC	Wisconsin Place Land and Infrastructure	33.33	%	(3)	29,969		30,375
500 North Capitol Venture LLC	500 North Capitol Street, NW	30.00	%		(11,630)		(10,253)
501 K Street LLC	1001 6th Street	50.00	%		45,955		44,774
Podium Developer LLC	The Hub on Causeway - Podium	50.00	%		42,916		45,201
Residential Tower Developer LLC	Hub50House	50.00	%		38,116		40,235
Hotel Tower Developer LLC	The Hub on Causeway - Hotel Air Rights	50.00	%		14,076		13,494
Office Tower Developer LLC	100 Causeway Street	50.00	%		56,055		57,660
1265 Main Office JV LLC	1265 Main Street	50.00	%		3,515		3,585
BNY Tower Holdings LLC	Dock 72	50.00	%	(4)	(7,065)		(11,890)

CA-Colorado Center, LLC	Colorado Center	50.00	%		234,972		237,815
7750 Wisconsin Avenue LLC	7750 Wisconsin Avenue	50.00	%		48,814		50,064
BP-M 3HB Venture LLC	3 Hudson Boulevard	25.00	%		113,288		115,103
Platform 16 Holdings LP	Platform 16	55.00	%		55,381		45,564
Gateway Portfolio Holdings LLC	Gateway Commons	50.00	%		393,679		376,834
Rosecrans-Sepulveda Partners 4, LLC	Beach Cities Media Campus	50.00	%		27,051		27,034
Safeco Plaza REIT LLC	Safeco Plaza	33.67	%	(5)	47,510		44,734
360 PAS Holdco LLC	360 Park Avenue South	71.11	%	(6)	69,538		42,988
PR II/BXP Reston Gateway LLC	Skymark - Reston Next Residential	20.00	%		15,359		15,184
751 Gateway Holdings LLC	751 Gateway	49.00	%		98,882		93,411
200 Fifth Avenue JV LLC	200 Fifth Avenue	26.69	%		68,563		75,718
ABXP Worldgate Investments LLC	13100 and 13150 Worldgate Drive	50.00	%		18,247		17,546
					$	1,391,149	$	1,337,416

_______________

$10.0 million, as described in Note 3 and this Note 5. Since then, the Company accounts for its assets, liabilities and operations on a consolidated basis.

(4)This property includes net equity balances from the amenity joint venture.

Schedule Of Balance Sheets Of The Unconsolidated Joint Ventures [Text Block]

The combined summarized balance sheets of the Company’s unconsolidated joint ventures are as follows:


	September 30, 2024		December 31, 2023
	(in thousands)
ASSETS
Real estate and development in process, net (1)	$	5,756,008	$	5,811,763
Other assets (2)	651,956		682,291
Total assets	$	6,407,964	$	6,494,054
LIABILITIES AND MEMBERS’/PARTNERS’ EQUITY
Mortgage and notes payable, net	$	3,198,547	$	3,351,873
Other liabilities (3)	294,795		361,357
Members’/Partners’ equity	2,914,622		2,780,824
Total liabilities and members’/partners’ equity	$	6,407,964	$	6,494,054
Company’s share of equity	$	1,334,102	$	1,278,483
Basis differentials (4)	57,047		58,933
Carrying value of the Company’s investments in unconsolidated joint ventures (5)	$	1,391,149	$	1,337,416

_______________

(1)At September 30, 2024 and December 31, 2023, this amount included right of use assets - operating leases totaling approximately $19.2 million and $20.1 million, respectively.

(2)At September 30, 2024 and December 31, 2023, this amount included sales-type lease receivable, net totaling approximately $14.1 million and $13.9 million, respectively.

(3)At September 30, 2024 and December 31, 2023, this amount included lease liabilities - operating leases totaling approximately $30.5 million.


	September 30, 2024		December 31, 2023
Property	(in thousands)
Colorado Center	$	296,758	$	298,906
200 Fifth Avenue	51,779		58,308
Gateway Commons	51,009		48,971
Safeco Plaza	(29,032)		(29,678)
360 Park Avenue South	(114,202)		(116,534)
Dock 72	(92,930)		(95,521)
Platform 16	(142,670)		(143,052)

These basis differentials (excluding land) will be amortized over the remaining lives of the related assets and liabilities.

Statements Of Operations Of The Joint Ventures

The combined summarized statements of operations of the Company’s unconsolidated joint ventures are as follows:


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Total revenue (1)	$	128,435	$	153,551	$	378,981	$	469,745
Expenses
Operating	53,280		65,119		148,929		183,348
Transaction costs	53		78		61		179
Depreciation and amortization	41,082		49,840		118,901		151,051
Total expenses	94,415		115,037		267,891		334,578
Other income (expense)
Loss from early extinguishment of debt	—		—		—		(3)
Interest expense	(45,244)		(60,737)		(132,106)		(176,786)
Unrealized gain (loss) on derivative instruments	(19,172)		10,242		(8,212)		14,089


Net loss	$	(30,396)	$	(11,981)	$	(29,228)	$	(27,533)

Company’s share of net loss	$	(9,319)	$	(4,476)	$	(9,105)	$	(10,739)

Gain on investment (2)	—		35,756		—		35,756
Gain on sale / consolidation	—		—		21,696		—
Impairment losses on investments (3)	—		(272,603)		—		(272,603)
Basis differential (4)	2,308		(6,233)		(6,215)		(14,207)
Income (loss) from unconsolidated joint ventures	$	(7,011)	$	(247,556)	$	6,376	$	(261,793)

_______________

(2)During the three months ended September 30, 2023, the Company completed a restructuring of its ownership in Metropolitan Square.

Consolidated Statements Of Comprehensive Income - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Net income (loss)

$ 108,452

$ (103,543)

$ 322,005

$ 138,269

Other comprehensive income (loss) :

Effective portion of interest rate contracts

(32,263)

5,459

(14,976)

13,886

Amortization of interest rate contracts

^[1]

3,077

1,677

9,518

5,026

Other comprehensive income (loss)

(29,186)

7,136

(5,458)

18,912

Comprehensive income (loss)

79,266

(96,407)

316,547

157,181

Net income attributable to noncontrolling interests

(24,824)

(8,283)

(78,879)

(67,979)

Other comprehensive (income) loss attributable to noncontrolling interest

2,913

(864)

177

(2,327)

Comprehensive income (loss) attributable to BXP, Inc.

57,355

(105,554)

237,845

86,875

Boston Properties Limited Partnership

Net income (loss)

110,156

(101,787)

327,109

143,569

Other comprehensive income (loss) :

Effective portion of interest rate contracts

(32,263)

5,459

(14,976)

13,886

Amortization of interest rate contracts

^[2]

3,077

1,677

9,518

5,026

Other comprehensive income (loss)

(29,186)

7,136

(5,458)

18,912

Comprehensive income (loss)

80,970

(94,651)

321,651

162,481

Net income attributable to noncontrolling interests

(15,381)

(21,053)

(50,715)

(59,769)

Comprehensive income (loss) attributable to BXP, Inc.

$ 65,589

$ (115,704)

$ 270,936

$ 102,712

[1]	Amounts reclassified from comprehensive income primarily to interest expense within BXP, Inc.’s Consolidated Statements of Operations
[2]	Amounts reclassified from comprehensive income primarily to interest expense within Boston Properties Limited Partnership’s Consolidated Statements of Operations.

Summary Of Significant Accounting Policies

9 Months Ended

Sep. 30, 2024

Accounting Policies [Abstract]

Summary Of Significant Accounting Policies

2. Summary of Significant Accounting Policies

BXP does not have any other significant assets, liabilities or operations, other than its investment in BPLP, nor does it have employees of its own. BPLP, not BXP, generally executes all significant business relationships other than transactions involving securities of BXP. All majority-owned subsidiaries and joint ventures over which the Company has financial and operating control and variable interest entities (“VIEs”) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income.

The accompanying interim financial statements are unaudited; however, the financial statements have been prepared in accordance with generally accepted accounting principles (“GAAP”) for interim financial information and in conjunction with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Accordingly, they do not include all of the disclosures required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting solely of normal recurring matters) necessary for a fair statement of the financial statements for these interim periods have been included. The results of operations for the interim periods are not necessarily indicative of the results to be obtained for other interim periods or for the full fiscal year. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosure required by GAAP. These financial statements should be read in conjunction with the Company’s financial statements and notes thereto contained in the Company’s Annual Report in the Company’s Form 10-K for its fiscal year ended December 31, 2023.

The Company bases its estimates on historical experience and on various other assumptions that it considers to be reasonable under the circumstances, including the impact of extraordinary events, the results of which form the basis for making significant judgments about the carrying values of assets and liabilities, assessments of future collectability, and other areas of the financial statements that are impacted by the use of estimates. Actual results may differ from these estimates under different assumptions or conditions.

Variable Interest Entities (VIEs)

Consolidated VIEs are those for which the Company is considered to be the primary beneficiary of a VIE. The primary beneficiary is the entity that has a controlling financial interest in the VIE, which is defined by the entity having both of the following characteristics: (1) the power to direct the activities that, when taken together, most significantly impact the VIE’s performance and (2) the obligation to absorb losses or the right to receive the returns from the VIE that could potentially be significant to the VIE. The assets of each VIE are only available to satisfy such VIE's respective liabilities. The Company has identified nine entities that are VIEs as of September 30, 2024 and has determined that it is the primary beneficiary for all of these entities as of September 30, 2024.

Consolidated Variable Interest Entities

As of September 30, 2024, BXP has identified nine consolidated VIEs, including BPLP. Excluding BPLP, the consolidated VIEs consisted of (i) the following five in-service properties: 767 Fifth Avenue (the General Motors Building), Times Square Tower, 601 Lexington Avenue, Atlantic Wharf Office Building and 100 Federal Street, (ii) 343 Madison Avenue, which is categorized as land held for future development and (iii) 290 Binney Street and 300 Binney Street, which are currently under development / redevelopment (See Note 14).

The Company consolidates these VIEs because it is the primary beneficiary. The third parties’ interests in these consolidated entities (excluding BPLP’s interest) are reflected as noncontrolling interests in property partnerships in the accompanying consolidated financial statements (See Note 9).

In addition, BXP’s only significant asset is its investment in BPLP and, consequently, substantially all of BXP’s assets and liabilities are the assets and liabilities of BPLP.

Variable Interest Entities Not Consolidated

As of September 30, 2024, the Company does not have any unconsolidated joint ventures that are classified as VIEs.

Fair Value Measurements


Financial Instrument			Level
3-Month United States Treasury Bills			Level 1
Unsecured commercial paper			Level 1
Investment in securities			Level 1
Unsecured senior notes (1)			Level 1
Related party note receivable			Level 3
Notes receivable			Level 3
Sales-type lease receivable			Level 3
Mortgage notes payable			Level 3
Unsecured line of credit			Level 3
Unsecured term loans			Level 3

_______________

(1)If trading volume for the period is low, the valuation could be categorized as Level 2.

Because the Company’s valuations of its financial instruments are based on the above Levels and involve the use of estimates, the actual fair values of its financial instruments may differ materially from those estimates. In addition, the Company’s estimated fair values for these instruments as of the end of the applicable reporting period are not projections of, nor necessarily indicative of, estimated or actual fair values in future reporting periods.

At September 30, 2024 and December 31, 2023, the Company had outstanding three-month United States Treasury Bills with a maturity date of November 21, 2024 and January 30, 2024, respectively, that were classified as held to maturity because the Company determined that it had the positive intent and ability to hold to maturity. Because these securities are considered short-term investments, they are reflected at amortized cost within Cash and Cash Equivalents on the Consolidated Balance Sheets. At September 30, 2024 and December 31, 2023, the amortized cost of these securities were approximately $175.9 million and $302.7 million, respectively.

At September 30, 2024, the Company had $500.0 million outstanding under its unsecured commercial paper program (See Note 6). Due to their short-term maturity and stated interest rates at approximate current market rates, the fair value of outstanding commercial paper borrowings approximates the Company's carrying amount at September 30, 2024.

The Company’s investment in non-real estate investments is shown within Prepaid and Other Assets on the Consolidated Balance Sheets and was approximately $6.7 million and $4.6 million at September 30, 2024 and December 31, 2023, respectively. The non-real estate investments utilize net asset value as the practical expedient.

Non-Recurring Fair Value


	September 30, 2024				December 31, 2023
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
3-Month United States Treasury Bills (1)	$	175,944	$	175,944	$	302,746	$	302,746

Related party note receivable, net	$	88,788	$	90,138	$	88,779	$	90,593
Note receivable, net	3,937		4,799		1,714		1,677
Sales-type lease receivable, net	14,429		13,563		13,704		13,338
Total	$	107,154	$	108,500	$	104,197	$	105,608

Mortgage notes payable, net	$	4,275,155	$	3,907,688	$	4,166,379	$	3,705,513
Unsecured senior notes, net	10,642,033		10,191,058		10,491,617		9,697,393
Unsecured line of credit	—		—		—		—
Unsecured term loans, net	798,058		800,303		1,198,301		1,196,945
Unsecured commercial paper	500,000		500,000		—		—
Total	$	16,215,246	$	15,399,049	$	15,856,297	$	14,599,851

_______________

At March 31, 2024, the Company evaluated the expected hold period for a portion of its Shady Grove property, consisting of 2 Choke Cherry Road, 2094 Gaither Road and a land parcel, located in Rockville, Maryland. Based on a shorter-than-expected hold period, the Company reduced the carrying value of a portion of the property that the Company anticipates selling to a third-party developer to its estimated fair value at March 31, 2024. As a result, during the nine months ended September 30, 2024, each of BXP and BPLP recognized an impairment loss of approximately $13.6 million. The Company’s estimated fair value utilized Level 3 inputs and was based on a pending offer from a third party (See Note 3).

Recurring Fair Value

Derivatives

In addition to the financial instruments noted above, the Company uses interest rate swap agreements to manage its interest rate risk (See Note 7). The valuation of these instruments is determined using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. To comply with the provisions of ASC 820, the Company incorporates credit valuation adjustments to appropriately reflect both its own nonperformance risk and the respective counterparty’s nonperformance risk in the fair value measurements. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with its derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. The Company assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and determined that the credit valuation adjustments were not significant to the overall valuation of its derivatives. As a result, the Company has determined that its derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy.

The following table presents the aggregate fair value of the Company’s interest rate swaps as of September 30, 2024 and December 31, 2023 (in thousands):


Fair value	September 30, 2024		December 31, 2023
Interest rate swaps	$	(10,191)	$	1,976

Investments

The Company accounts for investments in equity securities at fair value, with gains or losses resulting from changes in fair value recognized currently in earnings. The Company maintains deferred compensation plans that are designed to allow officers and non-employee directors of BXP to defer a portion of the officer’s current income or the non-employee director’s current compensation on a pre-tax basis and receive a tax-deferred return on these deferrals based on the performance of specific investments selected by the officer or non-employee director. The Company’s obligation under the plans is that of an unsecured promise to pay the deferred compensation to the plan participants in the future. At September 30, 2024 and December 31, 2023, the Company had maintained approximately $38.9 million and $36.1 million, respectively, in separate accounts, which are not restricted as to their use. The Company recognized gains (losses) of approximately $2.2 million and $(0.9) million on its investments in the accounts associated with the Company’s deferred compensation plans during the three months ended September 30, 2024 and September 30, 2023, respectively, and approximately $4.8 million and $2.3 million during the nine months ended September 30, 2024 and September 30, 2023, respectively, primarily due to the observable change in fair value.

Noncontrolling Interests

9 Months Ended

Sep. 30, 2024

Noncontrolling Interest [Abstract]

Noncontrolling Interest Disclosure [Text Block]

9. Noncontrolling Interests


OP Units	LTIP Units (1)	2022 MYLTIP Units	2023 MYLTIP Units	2024 MYLTIP Units
15,926,014	2,336,797	252,151	322,053	330,479

__________

(1)Includes 617,961 LTIP Units earned by employees under the Company’s multi-year long-term incentive awards granted between 2012 and 2021 (i.e., 2012 OPP and 2013 - 2021 MYLTIP awards).

Noncontrolling Interest—Common Units

During the nine months ended September 30, 2024, 951,881 OP Units were presented by the holders for redemption (including an aggregate of 105,814 OP Units issued upon conversion of LTIP Units, 2012 OPP Units and MYLTIP Units) and were redeemed by BXP in exchange for an equal number of shares of Common Stock.

At September 30, 2024, BPLP had outstanding the 2022 - 2024 MYLTIP Units. Prior to the end of the respective three-year performance period for each plan, holders of MYLTIP Units are entitled to receive per unit distributions equal to one-tenth (10%) of the regular quarterly distributions payable on an OP Unit, but will not be entitled to receive any special distributions. After the three-year performance period for each plan has ended, (1) the number of MYLTIP Units, both vested and unvested, that MYLTIP award recipients have earned, if any, based on the establishment of a performance pool, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on an OP Unit and (2) with respect to the 2022 - 2024 MYLTIP Units, the Company will make a “catch-up” cash payment on the MYLTIP Units that are ultimately earned in an amount equal to the regular and special dividends, if any, declared during the performance period on a number of shares of Common Stock agreed to the number of 2022 - 2024 MYLTIP Units that are earned, less the distributions actually paid during the performance period on all of the awarded 2022 - 2024 MYLTIP Units.

On February 1, 2024, the measurement period for the Company’s 2021 MYLTIP awards ended and, based on BXP’s absolute and relative TSR performance, the final payout was determined to be 112% of target, or an aggregate of approximately $12.6 million (after giving effect to employee separations). As a result, an aggregate of 155,625 2021 MYLTIP Units that had been previously granted were automatically forfeited.

The following table presents BPLP’s distributions on the OP Units and LTIP Units and MYLTIP Units paid or declared in 2024 and during the nine months ended September 30, 2023:


Record Date	Payment Date	Distributions per OP Unit and LTIP Unit	Distributions per MYLTIP Unit
September 30, 2024	October 31, 2024	$0.98	$0.098
June 28, 2024	July 31, 2024	$0.98	$0.098
March 28, 2024	April 30, 2024	$0.98	$0.098
December 29, 2023	January 30, 2024	$0.98	$0.098
September 29, 2023	October 31, 2023	$0.98	$0.098
June 30, 2023	July 31, 2023	$0.98	$0.098
March 31, 2023	April 28, 2023	$0.98	$0.098
December 30, 2022	January 30, 2023	$0.98	$0.098

A holder of an OP Unit may present the OP Unit to BPLP for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, BPLP must redeem the OP Unit for cash equal to the then value of a share of Common Stock of BXP. BXP may, in its sole discretion, elect to assume and satisfy the redemption obligation by paying either cash or issuing one share of Common Stock. The value of the OP Units (other than OP Units owned by BXP), and LTIP Units (including the 2012 OPP Units and 2013 - 2021 MYLTIP Units), assuming in each case that all conditions had been met for the conversion thereof, had all of such units been redeemed at September 30, 2024 was approximately $1.5 billion

based on the last reported price of a share of Common Stock on the New York Stock Exchange of $80.46 per share on September 30, 2024.

Noncontrolling Interests—Property Partnerships

The noncontrolling interests in property partnerships consist of the outside equity interests in ventures that are consolidated with the financial results of the Company because the Company exercises control over the entities that own the properties. The equity interests in these ventures that are not owned by the Company, totaling approximately $1.9 billion and $1.6 billion at September 30, 2024 and December 31, 2023, respectively, are included in Noncontrolling Interests—Property Partnerships on the accompanying Consolidated Balance Sheets.

On March 21, 2024, the Company completed the sale of a 45% interest in 290 Binney Street in Cambridge, Massachusetts.  The institutional investor funded approximately $97.2 million in cash at closing, which is less than 45% of the agreed upon carrying value of the property immediately prior to the transaction.  The institutional investor will fund all construction costs until its equity balance is proportionate to its ownership percentage, after which the Company and the institutional investor will fund the development project based on their respective ownership interests.  The Company retains a 55% ownership interest in the joint venture.  The transaction did not qualify as a sale of real estate for financial reporting purposes as the Company continues to effectively control the property and thus will continue to account for the property on a consolidated basis in its financial statements and no gain was recognized in the Consolidated Statements of Operations.  The Company provides customary development, property management and leasing services to the joint venture. 

The Company has accounted for the transaction as an equity transaction and as of March 21, 2024 has recognized noncontrolling interest in its Consolidated Balance Sheets totaling approximately $104.6 million, which is equal to 45% of the aggregate carrying value of the total equity of the property immediately prior to the transaction.  The difference between the cash proceeds received and the noncontrolling interest recognized, which was approximately $7.5 million, has been reflected as a decrease in additional paid-in capital in the Company’s Consolidated Balance Sheets.  At the end of each reporting period, there will be a reallocation of the partners’ equity balances such that the ending balance in each partners’ capital account reflects each partners’ claim on net assets. These adjustments will impact additional paid-in capital and noncontrolling interest in property partnerships in the Company’s Consolidated Balance Sheets. For the three and nine months ended September 30, 2024, the adjustment was approximately $(27.1) million and $7.8 million, respectively. 

290 Binney Street is an approximately 573,000 net rentable square foot laboratory/life sciences development project located in Cambridge, Massachusetts.  The  development project is 100% pre-leased to a life sciences company.

Real Estate

9 Months Ended

Sep. 30, 2024

Real Estate [Abstract]

Real Estate

3. Real Estate

BXP

Real estate consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Land	$	5,318,724	$	5,251,224
Right of use assets - finance leases (1)	372,896		401,680
Right of use assets - operating leases (1)	339,804		324,298
Land held for future development (2)	690,774		697,061
Buildings and improvements	16,898,821		16,607,756
Tenant improvements	3,782,391		3,592,172
Furniture, fixtures and equipment	54,992		53,716
Construction in progress	812,122		547,280
Total	28,270,524		27,475,187
Less: Accumulated depreciation	(7,369,545)		(6,881,728)
	$	20,900,979	$	20,593,459

_______________

(1)See Note 4.

(2)Includes pre-development costs.

BPLP

Real estate consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Land	$	5,224,015	$	5,156,515
Right of use assets - finance leases (1)	372,896		401,680
Right of use assets - operating leases (1)	339,804		324,298
Land held for future development (2)	690,774		697,061
Buildings and improvements	16,627,265		16,336,200
Tenant improvements	3,782,391		3,592,172
Furniture, fixtures and equipment	54,992		53,716
Construction in progress	812,122		547,280
Total	27,904,259		27,108,922
Less: Accumulated depreciation	(7,241,074)		(6,758,361)
	$	20,663,185	$	20,350,561

_______________

(1)See Note 4.

(2)Includes pre-development costs.

Acquisition

On January 8, 2024, the Company completed the acquisition of its joint venture partner’s 50% economic ownership interest in the joint venture that owns 901 New York Avenue, located in Washington, DC. At acquisition, the total net equity acquired was $20.0 million, which includes $10.0 million in cash that the Company paid for the joint venture partner's 50% economic ownership interest in the joint venture. The property is subject to existing mortgage indebtedness of approximately $207.1 million (See Note 6). The acquisition resulted in the Company recording a gain upon consolidation of approximately $21.8 million, which is the difference between the fair value of the previously held equity method investment immediately prior to the consolidation of $10.0 million, less the Company’s costs basis of approximately $(11.8) million. The gain on consolidation is included within income (loss) from unconsolidated joint ventures in the Consolidated Statement of Operations.

The total net assets acquired is equal to (1) the total net equity acquired of $20.0 million, which includes $10.0 million in cash that the Company paid for the joint venture partner's 50% economic ownership interest in the joint venture plus (2) $207.1 million of debt assumed, less (3) net working capital acquired of approximately $7.1 million. The following table summarizes the allocation of the fair value of the net assets the Company received at the date of acquisition for 901 New York Avenue (in thousands):


Land and site improvements	$	65,808
Building and improvements	56,882
Tenant improvements	16,088
In-place lease intangibles	72,621
Above-market lease intangibles	2,757
Below-market lease intangibles	(2,515)
Mortgage note payable adjustment	8,374
Net assets acquired	$	220,015


	Acquired In-Place Lease Intangibles		Acquired Above-Market Lease Intangibles		Acquired Below-Market Lease Intangibles
Period from January 8, 2024 through December 31, 2024	$	10,364	$	607	$	252
2025	9,030		454		257
2026	6,494		238		257
2027	6,265		201		257
2028	6,069		186		257
2029	6,076		186		251


	Acquired In-Place Lease Intangibles	Acquired Above-Market Lease Intangibles	Acquired Below-Market Lease Intangibles
Weighted-average useful life	6.7	4.0	9.8

901 New York Avenue contributed approximately $24.7 million of revenue and $6.9 million of net loss to the Company for the period from January 8, 2024 through September 30, 2024. 901 New York Avenue is an office property consisting of approximately 524,000 net rentable square feet.

Development

On February 12, 2024, the Company commenced the development of a residential project at 121 Broadway Street in Cambridge, Massachusetts that is adjacent to its development projects at 290 Binney Street and 300 Binney Street. 121 Broadway will consist of 439 residential units aggregating approximately 492,000 net rentable square feet. There can be no assurance that the Company will complete development of the project on the terms and schedule currently contemplated or at all.

On April 5, 2024, the Company completed and fully placed in-service 760 Boylston Street, an approximately 118,000 net rentable square foot retail redevelopment located in Boston, Massachusetts.

On July 17, 2024, the Company partially placed in-service Reston Next Office Phase II, an approximately 90,000 net rentable square foot development project comprised of office and retail space located in Reston, Virginia.

On September 26, 2024, the Company fully placed in-service 180 CityPoint, an approximately 329,000 net rentable square foot laboratory/life sciences project located in Waltham, Massachusetts.

Pending Disposition and Impairment

At March 31, 2024, the Company evaluated the expected hold period for a portion of its Shady Grove property, consisting of 2 Choke Cherry Road, 2094 Gaither Road and a land parcel, located in Rockville, Maryland. Based on a shorter-than-expected hold period, the Company reduced the carrying value of a portion of the property that the Company anticipates selling to a third-party developer to its estimated fair value at March 31, 2024. As a result, each of BXP and BPLP recognized an impairment loss of approximately $13.6 million during the nine months ended September 30, 2024. The Company’s estimated fair value was based on Level 3 inputs as defined in ASC 820 and on a pending offer from a third-party.

On May 7, 2024, the Company entered into an agreement with the third-party developer for the sale of 2 Choke Cherry Road, 2094 Gaither Road and the land parcel for an aggregate gross sale price of approximately $24.8 million. On July 22, 2024, the Company executed an amendment to the agreement for an aggregate gross sale price of approximately $24.7 million. 2 Choke Cherry Road and 2094 Gaither Road are two vacant office properties aggregating approximately 143,000 net rentable square feet that were taken out of service and held for redevelopment. The disposition is subject to satisfaction of certain closing conditions and there can be no assurance that this transaction will be consummated on the terms currently contemplated or at all.