AVALONBAY COMMUNITIES INC

1. Organization, Basis of Presentation and Significant Accounting Policies

Organization and Basis of Presentation

AvalonBay Communities, Inc. (the “Company,” which term, unless the context otherwise requires, refers to AvalonBay Communities, Inc. together with its subsidiaries), is a Maryland corporation that has elected to be treated as a real estate investment trust (“REIT”) for federal income tax purposes under the Internal Revenue Code of 1986, as amended (the “Code”). The Company develops, redevelops, acquires, owns and operates multifamily communities in New England, the New York/New Jersey metro area, the Mid-Atlantic, the Pacific Northwest, and Northern and Southern California, as well as in the Company's expansion regions of Raleigh-Durham and Charlotte, North Carolina, Southeast Florida, Dallas and Austin, Texas, and Denver, Colorado.

At December 31, 2023, the Company owned or held a direct or indirect ownership interest in 299 operating apartment communities containing 90,669 apartment homes in 12 states and the District of Columbia, of which 18 communities were under development. The Company also owned or held a direct or indirect ownership interest in land or rights to land on which the Company expects to develop an additional 30 communities that, if developed as expected, will contain an estimated 10,801 apartment homes (unaudited).

Capitalized terms used without definition have meanings provided elsewhere in this Form 10-K.

Principles of Consolidation

The accompanying Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries, certain joint venture partnerships, subsidiary partnerships structured as DownREITs and any variable interest entities that qualify for consolidation. All significant intercompany balances and transactions have been eliminated in consolidation.

The Company accounts for joint venture entities and subsidiary partnerships in accordance with the consolidation guidance. The Company determines first whether to follow the variable interest entity (“VIE”) or the voting interest entity (“VOE”) model for each joint venture entity. The Company then evaluates whether it should consolidate the venture. Under the VIE model, the Company consolidates an investment when it has control to direct the activities of the venture and the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company's maximum exposure for its VIEs is limited to its investments in the respective VIEs. Under the VOE model, the Company consolidates an investment when (i) it controls the investment through ownership of a majority voting interest if the investment is not a limited partnership or (ii) it controls the investment through its ability to remove the other partners in the investment, at its discretion, when the investment is a limited partnership.

The Company generally uses the equity method of accounting for its investment in joint ventures, including when the Company holds a noncontrolling limited partner interest in a joint venture. Any investment in excess of the Company's cost basis at acquisition or formation of an equity method venture, will be recorded as a component of the Company's investment in the joint venture and recognized over the life of the underlying fixed assets of the venture as a reduction to its equity in income from the venture. Investments in which the Company has little or no influence are accounted for using the measurement alternative with the carrying amount of the investment adjusted to fair value when there is an observable transaction indicating a change in fair value.

Real Estate

Operating real estate assets are stated at cost and consist of land and improvements, buildings and improvements, furniture, fixtures and equipment, and other costs incurred during their development, redevelopment and acquisition. Significant expenditures which improve or extend the life of an existing asset and that will benefit the Company for periods greater than a year, are capitalized. Expenditures for maintenance and repairs are charged to expense as incurred.

Project costs related to the development, construction and redevelopment of real estate projects (including interest and related loan fees, property taxes and other direct costs) are capitalized as a cost of the project. Indirect project costs that relate to several projects are capitalized and allocated to the projects to which they relate. Indirect costs not clearly related to development, construction and redevelopment activity are expensed as incurred. For development, capitalization (i) begins when the Company has determined that development of the future asset is probable, (ii) can be suspended if there is no current development activity underway, but future development is still probable and (iii) ends when the asset, or a portion of an asset, is ready for its intended use, or the Company's intended use changes such that capitalization is no longer appropriate.

For land parcels acquired for development improved with operating real estate, the Company generally manages the improvements until all tenant obligations have been satisfied or eliminated through negotiation, and construction of new apartment communities is ready to begin. Revenue from incidental operations received from the current improvements on land parcels in excess of any incremental costs are recorded as a reduction of total capitalized costs of the respective Development Right and not as part of net income. Incidental operating costs in excess of incidental operating income are expensed in the period incurred.

For redevelopment efforts, the Company capitalizes costs either (i) in advance of taking homes out of service when significant renovation of the common area has begun until the redevelopment is completed, or (ii) when an apartment home is taken out of service for redevelopment until the redevelopment is completed and the apartment home is available for a new resident. Rental income and operating costs incurred during the initial lease-up or post-redevelopment lease-up period are recognized in earnings.

The Company accounts for real estate acquisitions as either an asset acquisition or a business combination. Under either model, the Company identifies and determines the fair value of any assets acquired, liabilities assumed and any noncontrolling interest in the acquiree. The Company generally views acquisitions of individual operating communities as asset acquisitions, which results in the capitalization of acquisition costs and the allocation of purchase price to the assets acquired and liabilities assumed, based on the relative fair value of the respective assets and liabilities.

Typical assets acquired and liabilities assumed include land, building, furniture, fixtures and equipment, debt and identified intangible assets and liabilities, consisting of the value of above or below market leases and in-place leases. The Company utilizes various sources to determine fair value, including its own analysis of recently acquired and existing comparable properties in its portfolio and other market data. The purchase price allocation to tangible assets is reflected in real estate assets and depreciated over their estimated useful lives. Any purchase price allocation to intangible assets, other than in-place lease intangibles, is included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets and amortized over the term of the acquired intangible asset. The Company values land based on a market approach, looking to recent sales of similar properties, adjusting for differences due to location, the state of entitlement as well as the shape and size of the parcel. Improvements to land are valued using a replacement cost approach and consider the structures and amenities included for the communities and is reduced by estimated depreciation. The value for furniture, fixtures and equipment is also determined based on a replacement cost approach, considering costs for both items in the apartment homes as well as common areas and is adjusted for estimated depreciation. The fair value of buildings is estimated using the replacement cost approach, assuming the buildings were vacant at acquisition. The replacement cost approach considers the composition of structures acquired, adjusted for depreciation which considers industry standard information and estimated useful life of the acquired property. The value of the lease-related intangibles considers the estimated cost of leasing the apartment homes as if the acquired building(s) were vacant, as well as the value of the current leases relative to market-rate leases. The in-place lease value is determined using an average total lease-up time, the number of apartment homes and net revenues generated during the lease-up time. Net revenues use market rent considering actual leasing and industry rental rate data. The value of current leases relative to a market-rate lease is based on market comparables. Given the heterogeneous nature of multifamily real estate, the fair values for the land, debt, real estate assets and in-place leases incorporate significant unobservable inputs and therefore are considered to be Level 3 prices within the fair value hierarchy. Consideration for acquisitions is typically in the form of cash unless otherwise disclosed.

Depreciation is generally calculated on a straight-line basis over the estimated useful lives of the assets, which for buildings and related improvements range from seven years to 30 years and for furniture, fixtures and equipment range from three years toseven years.

Income Taxes

The Company elected to be treated as a REIT for federal income tax purposes for its tax year ended December 31, 1994 and has not revoked such election. A REIT is a corporate entity which holds real estate interests and can deduct from its federally taxable income qualifying dividends it pays if it meets a number of organizational and operational requirements, including a requirement that it distribute at least 90% of its adjusted taxable income to stockholders. Therefore, as a REIT, the Company generally will not be subject to corporate level federal income tax on its taxable income if it annually distributes 100% of its taxable income to its stockholders.

The states in which the Company operates have similar tax provisions which recognize the Company as a REIT for state income tax purposes. Management believes that all such conditions for the exemption from income taxes on ordinary income have been or will be met for the periods presented. Accordingly, no provision for federal and state income taxes has been made. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal corporate income taxes at regular corporate rates and may not be able to qualify as a corporate REIT for four subsequent taxable years. Even if the Company qualifies for taxation as a REIT, the Company may be subject to certain state and local taxes on its income and property, and to federal income and excise taxes on its undistributed taxable income and in certain other instances.

Taxable income from activities performed through taxable REIT subsidiaries (“TRS”) is subject to federal, state and local income taxes. The Company recognized income tax expense, primarily due to dispositions at The Park Loggia, of $10,153,000, $14,646,000 and $5,733,000 in 2023, 2022 and 2021, respectively. As of December 31, 2023 and 2022, the Company didnot have any unrecognized tax positions. The Company does not believe that there will be any material changes in its unrecognized tax positions over the next 12 months. The Company is subject to examination by the respective taxing authorities for the tax years 2020 through 2022.

The following summarizes the tax components of the Company's common dividends declared for the years ended December 31, 2023, 2022 and 2021 (unaudited):

Deferred Financing Costs

Deferred financing costs include expenditures necessary to obtain debt financing and are amortized on a straight-line basis, which approximates the effective interest method, over the shorter of the loan term or the related credit enhancement facility, if applicable. Unamortized financing costs are charged to earnings when debt is retired before the maturity date. Accumulated amortization of deferred financing costs for unsecured notes was $34,494,000 and $29,815,000 as of December 31, 2023 and 2022, respectively, and related to mortgage notes payable was $2,262,000 and $2,040,000 as of December 31, 2023 and 2022, respectively. Deferred financing costs, except for costs associated with line-of-credit arrangements, are presented as a direct deduction from the related debt liability. Accumulated amortization of deferred financing costs for the Company's Credit Facility was $14,490,000 and $11,222,000 as of December 31, 2023 and 2022, respectively, and deferred financing costs net of accumulated amortization was included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.

Cash, Cash Equivalents and Restricted Cash

Cash and cash equivalents includes all cash and liquid investments with an original maturity of three months or less from the date acquired. Restricted cash includes principal reserve funds that are restricted for the repayment of specified secured financing, amounts the Company has designated for planned 1031 exchange activity and resident security deposits. The majority of the Company's cash, cash equivalents and restricted cash are held at major commercial banks.

Interest Rate Contracts

The Company utilizes derivative financial instruments to manage interest rate risk. See Note 11, “Fair Value,” for further discussion of derivative financial instruments.

Comprehensive Income

Comprehensive income, as reflected on the Consolidated Statements of Comprehensive Income, is defined as all changes in equity during each period except for those resulting from investments by or distributions to shareholders. Accumulated other comprehensive income (loss), as reflected on the Consolidated Statements of Equity, reflects the effective portion of the cumulative changes in the fair value of derivatives in qualifying cash flow hedge relationships.

Earnings per Common Share

Basic earnings per common share is computed by dividing net income attributable to common stockholders by the weighted average number of shares outstanding during the period. All outstanding unvested restricted share awards contain rights to non-forfeitable dividends and participate in undistributed earnings with common shareholders and, accordingly, are considered participating securities that are included in the two-class method of computing basic earnings per common share. Both the unvested restricted shares and other potentially dilutive common shares, and the related impact to earnings, are considered when calculating earnings per common share on a diluted basis. Diluted earnings per common share was computed using the treasury stock method for performance awards, options and participating securities. The Company's earnings per common share are determined as follows (dollars in thousands, except per share data):

Certain options to purchase shares of common stock in the amounts of 303,784 and 291,881 were outstanding as of December 31, 2023 and 2022, respectively, but were not included in the computation of diluted earnings per common share because such options were anti-dilutive for the period. All options to purchase shares of common stock outstanding as of December 31, 2021 are included in the computation of diluted earnings per common share.

Expensed Transaction, Development and Other Pursuit Costs

The Company capitalizes costs associated with its development activities to the basis of land held when future development is probable (“Development Rights”), or if the Company has either not yet acquired the land or if the project is subject to a leasehold interest, the costs are capitalized as deferred development costs. Future development of these Development Rights is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and the availability of capital. Costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the Company determines a Development Right is no longer probable, the Company recognizes any necessary expense to write down its basis in the Development Right. The Company expensed costs related to development pursuits not yet considered probable for development and the abandonment of Development Rights, as well as costs incurred in pursuing the acquisition or disposition of assets for which such acquisition and disposition activity did not occur, in the amounts of $33,479,000, $16,565,000 and $2,192,000 during the years ended December 31, 2023, 2022 and 2021, respectively. These costs are included in expensed transaction, development and other pursuit costs, net of recoveries on the accompanying Consolidated Statements of Comprehensive Income. The amount for 2023 includes write-offs of $27,455,000 related toseven Development Rights that the Company determined are no longer probable. The amount for 2022 includes write-offs of $10,073,000 related tothree development opportunities that the Company determined are no longer probable. These costs can vary greatly, and the costs incurred in any given period may be significantly different in future periods.

Casualty and Impairment of Long-Lived Assets

The Company evaluates its real estate and other long-lived assets for impairment when potential indicators of impairment exist. Such assets are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of an asset may not be recoverable, the Company assesses its recoverability by comparing the carrying amount of the asset to its estimated undiscounted future cash flows. If the carrying amount exceeds the aggregate undiscounted future cash flows, the Company recognizes an impairment loss to the extent the carrying amount exceeds the estimated fair value of the asset. Based on periodic tests of recoverability of long-lived assets, for the years ended December 31, 2023, 2022 and 2021, the Company didnot recognize any material impairment losses. During the year ended December 31, 2023, the Company recognized a charge of $9,118,000 for the property and casualty damages across certain communities in its Northeast and California regions related to severe weather and other casualty events, reported as casualty loss on the accompanying Consolidated Statements of Comprehensive Income. During the year ended December 31, 2021, the Company recognized a charge of $3,119,000 related to damage across several communities in our East Coast markets from severe storms and a fire at an operating community, reported as casualty loss on the accompanying Consolidated Statements of Comprehensive Income.

The Company evaluates its unconsolidated investments for other than temporary impairment, considering both whether the carrying value of the investment exceeds the fair value, and the Company’s intent and ability to hold the investment to recover its carrying value. The Company also evaluates its proportionate share of any impairment of assets held by unconsolidated investments. The Company didnot recognize any other than temporary impairment losses during the years ended December 31, 2023, 2022 or 2021.

Assets Held for Sale and Discontinued Operations

The Company presents the assets and liabilities of any communities which have been sold, or otherwise qualify as held for sale, separately in the accompanying Consolidated Balance Sheets. In addition, the results of operations for those assets that meet the definition of discontinued operations are presented as such in the accompanying Consolidated Statements of Comprehensive Income. Real estate assets held for sale are measured at the lower of the carrying amount or the fair value less the cost to sell. Upon the classification of an asset as held for sale, no further depreciation is recorded. Disposals representing a strategic shift in operations (e.g., a disposal of a major geographic area, a major line of business or a major equity method investment) are presented as discontinued operations, and for those assets qualifying for classification as discontinued operations, the specific components of net income presented as discontinued operations include net operating income, depreciation expense and interest expense, net. For periods prior to the asset qualifying for discontinued operations, the Company reclassifies the results of operations to discontinued operations. In addition, the net gain or loss (including any impairment loss) on the eventual disposal of assets held for sale will be presented as discontinued operations when recognized. A change in presentation for held for sale or discontinued operations has no impact on the Company's financial condition or results of operations. The Company combines the operating, investing and financing portions of cash flows attributable to discontinued operations with the respective cash flows from continuing operations on the accompanying Consolidated Statements of Cash Flows. The Company hadno real estate assets that qualified as held for sale presentation at December 31, 2023.

Derivative Instruments and Hedging Activities

The Company enters into interest rate swap and interest rate cap agreements (collectively, “Hedging Derivatives”) for interest rate risk management purposes and in conjunction with certain variable rate secured debt to satisfy lender requirements. The Company does not enter into Hedging Derivatives for trading or other speculative purposes. The Company assesses the effectiveness of qualifying cash flow and fair value hedges, both at inception and on an ongoing basis. The fair values of Hedging Derivatives that are in an asset position are recorded in prepaid expenses and other assets. The fair values of Hedging Derivatives that are in a liability position are included in accrued expenses and other liabilities. Fair value changes for derivatives that are not in qualifying hedge relationships are reported as a component of interest expense, net. For the Hedging Derivatives that qualify as effective cash flow hedges, the Company has recorded the cumulative changes in the fair value of Hedging Derivatives in accumulated other comprehensive income. Amounts recorded in accumulated other comprehensive income will be reclassified into earnings in the periods in which earnings are affected by the hedged cash flow. The effective portion of the change in fair value of the Hedging Derivatives that qualify as effective fair value hedges is reported as an adjustment to the carrying amount of the corresponding hedged item. Receipts or payments associated with the gains and losses on the Company’s cash flow hedges are presented as a component of cash flows from financing activities in the period the hedges are terminated and the payments for the Company’s derivatives that are not qualifying for hedging relationships are presented as a component of cash flows from operating activities. See Note 11, “Fair Value,” for further discussion of derivative financial instruments.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States ("GAAP") requires management to make certain estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates.

Reclassifications

Certain reclassifications have been made to amounts in prior years' financial statements and notes to the financial statements to conform to current year presentations as a result of changes in held for sale classification, disposition activity, segment classification and classification of for-sale condominium inventory and activity.

Leases

The Company is party to leases as both a lessor and a lessee, primarily as follows:

•lessor of residential and commercial space within its apartment communities; and

•lessee under (i) ground leases for land underlying current operating or development communities and certain commercial and parking facilities and (ii) office leases for its corporate headquarters and regional offices.

Lessee Considerations

The Company assesses whether a contract is or contains a lease based on whether the contract conveys the right to control the use of an identified asset, including specified portions of larger assets, for a period of time in exchange for consideration.

The Company’s leases include both fixed and variable lease payments that are based on an index or rate such as the consumer price index (CPI) or percentage rents based on total sales. Variable lease payments are generally not included in the lease liability, but recognized as variable lease expense in the period in which they are incurred.

For leases that have options to extend the term or terminate the lease early, the Company only factored the impact of such options into the lease term if the option was considered reasonably certain to be exercised. The Company determined the discount rate associated with its ground and office leases on a lease-by-lease basis using the Company’s actual borrowing rates as well as indicative market pricing for longer term rates and taking into consideration the remaining term of the lease agreements. For leases that are 12 months or less, the Company elected the practical expedient to recognize the lease payments on a straight line basis.

Lessor Considerations

The Company's residential and commercial leases at its apartment communities are operating leases. For leases that include rent concessions and/or fixed and determinable rent increases, rental income is recognized on a straight-line basis over the noncancellable term of the lease, which, for residential leases, is generally one year. Some of the Company’s commercial leases have renewal options which the Company will only include in the lease term if, at the commencement of the lease, it is reasonably certain that the lessee will exercise this option.

For the Company’s leases, which are comprised of a lease component and common area maintenance as a non-lease component, the Company determined that (i) the leases are operating leases, (ii) the lease component is the predominant component and (iii) all components of its operating leases share the same timing and pattern of transfer.

Revenue and Gain Recognition

Under Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers, the Company recognizes revenue for the transfer of goods and services to customers for consideration that the Company expects to receive. The majority of the Company’s revenue is derived from residential and commercial rental and other lease income, which are accounted for as discussed above, under “Leases”. The Company's revenue streams that are not accounted for under ASC 842, Leases, include:

•Management fees - The Company has investment interests in real estate joint ventures, for which the Company may manage (i) the venture, (ii) the associated operating communities owned by the ventures and/or (iii) the construction, development or redevelopment of those communities. For these activities, the Company receives asset management, property management, development and/or redevelopment fee revenue. The performance obligation is the management of the venture, community or other defined task such as the development or redevelopment of the community. While the individual activities that comprise the performance obligation of the management fees can vary day to day, the nature of the overall performance obligation to provide management service is the same and considered by the Company to be a series of services that have the same pattern of transfer to the customer and the same method to measure progress toward satisfaction of the performance obligation. The Company also provides various third party back-office, financial administrative support services. The Company recognizes revenue for fees as earned.

•Non-lease related revenue - The Company recognizes revenue for items not considered to be components of a lease as earned.

•Gains or losses on sales of real estate -The Company accounts for the sale of real estate and any related gain recognition in accordance with the accounting guidance applicable to sales of real estate, which establishes standards for recognition of profit on all real estate sales transactions, other than commercial land sales. The Company recognizes the sale, and associated gain or loss from the disposition when the criteria for the sale of an asset have been met, which include when (i) a contract exists and (ii) the buyer obtained control of the nonfinancial asset that was sold.

The following table details the Company’s revenue disaggregated by reportable operating segment, further discussed in Note 8, “Segment Reporting,” for the years ended December 31, 2023, 2022 and 2021. The segments are classified based on the individual community's status at December 31, 2023 for the years ended December 31, 2023 and 2022, and at December 31, 2022 for the year ended December 31, 2021. Segment information for total revenue excludes real estate assets that were sold from January 1, 2021 through December 31, 2023, or otherwise qualify as held for sale as of December 31, 2023, as described in Note 6, “Real Estate Disposition Activities.” (dollars in thousands):

(1)Represents third-party property management, developer fees and miscellaneous income and other ancillary items which are not allocated to a reportable segment.

(2)Amounts include revenue streams related to leasing activities that are not considered components of a lease, and revenue streams not related to leasing activities including, but not limited to, application fees, renters insurance fees and vendor revenue sharing.

(3)Represents revenue accounted for under ASC 606.

(4)Represents residential and commercial rental and other lease income, accounted for under ASC 842.

Due to the nature and timing of the Company’s identified revenue streams, there were no material amounts of outstanding or unsatisfied performance obligations as of December 31, 2023.

Uncollectible Lease Revenue Reserves

The Company assesses the collectability of its lease revenue and receivables on an ongoing basis by (i) assessing the probability of receiving all lease amounts due on a lease-by-lease basis, (ii) reserving all amounts for those leases where collection of substantially all of the remaining lease payments is not probable and (iii) subsequently, will only recognize revenue to the extent cash is received. If the Company determines that collection of the remaining lease payments becomes probable at a future date, the Company will recognize the cumulative revenue that would have been recorded under the original lease agreement.

In addition to the specific reserves recognized under ASC 842, the Company also evaluates its lease receivables for collectability at a portfolio level under ASC 450, Contingencies – Loss Contingencies. The Company recognizes a reserve under ASC 450 when the uncollectible revenue is probable and reasonably estimable. The Company applies this reserve to the population of the Company’s revenue and receivables not specifically addressed as part of the specific ASC 842 reserve.

The Company recorded an aggregate offset to income for uncollectible lease revenue, net of amounts received from government rent relief programs, for its residential and commercial portfolios of $57,906,000, $49,147,000 and $52,075,000 for the years ended December 31, 2023, 2022 and 2021, respectively, under ASC 842 and ASC 450.

Recently Issued Accounting Standards

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting - Improvements to Reportable Segment Disclosures, which requires reportable segments disclosures of significant segment expenses provided to the chief operating decision maker (“CODM”). The standard does not change the definition of a segment, the method for determining segments, or the criteria for aggregating operating segments into reportable segments. The new standard will be effective for fiscal years beginning after December 15, 2023. The Company is assessing the standard and does not expect the standard to have a material effect on the Company’s financial position or results of operations.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures, which requires (i) a tabular rate reconciliation of the reported income tax expense (benefit) from continuing operations into specific categories, (ii) separate disclosure for any reconciling items within certain categories above a quantitative threshold, (iii) disclosure of income taxes paid disaggregated by federal, state and material jurisdictions and (iv) disclosure of income tax expense from continuing operations disaggregated by federal and state. The new standard will be effective for fiscal years beginning after December 15, 2024. The Company is assessing the standard and does not expect the standard to have a material effect on the Company’s financial position or results of operations.

2. Interest Capitalized

The Company capitalizes interest during the development and redevelopment of real estate assets. Capitalized interest associated with the Company's development or redevelopment activities totaled $47,133,000, $34,854,000 and $32,687,000 for the years ended December 31, 2023, 2022 and 2021, respectively.

3. Debt

The Company's debt, which consists of unsecured notes, the variable rate unsecured term loan (the “Term Loan”), mortgage notes payable, the Credit Facility and the Commercial Paper Program, each as defined below, as of December 31, 2023 and 2022 is summarized below. The following amounts and discussion do not include the mortgage notes related to the communities classified as held for sale, if any, as of December 31, 2023 and 2022, as shown in the accompanying Consolidated Balance Sheets (dollars in thousands) (see Note 6, “Real Estate Disposition Activities”). The weighted average interest rates in the following table for secured and unsecured notes include costs of financing such as credit enhancement fees, trustees' fees, the impact of interest rate hedges and mark-to-market adjustments.

(1) Excludes deferred financing costs and debt discount associated with the Credit Facility and Commercial Paper Program which are included in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.

The Company has a $2,250,000,000 revolving variable rate unsecured credit facility with a syndicate of banks (the “Credit Facility”) which matures in September 2026. The interest rate that would be applicable to borrowings under the Credit Facility was 6.19% at December 31, 2023 and was composed of (i) the Secured Overnight Financing Rate (“SOFR”), applicable to the period of borrowing for a particular draw of funds from the facility (e.g., one month to maturity, three months to maturity, etc.), plus (ii) the current borrowing spread to SOFR of 0.805% per annum, which consisted of a 0.10% SOFR adjustment plus 0.705% per annum, assuming a daily SOFR borrowing rate. The borrowing spread to SOFR can vary from SOFR plus 0.63% to SOFR plus 1.38% based upon the rating of the Company's unsecured senior notes. There is also an annual facility commitment fee of 0.12% of the borrowing capacity under the facility, which can vary from 0.095% to 0.295% based upon the rating of the Company's unsecured senior notes. The Credit Facility contains a sustainability-linked pricing component which provides for interest rate margin and commitment fee reductions or increases by meeting or missing targets related to environmental sustainability, specifically greenhouse gas emission reductions, with the adjustment determined annually. The first determination under the sustainability-linked pricing component occurred in July 2023, resulting in reductions of approximately 0.02% to the interest rate margin and 0.005% to the commitment fee due to our achievement of sustainability targets.

The availability on the Company's Credit Facility as of December 31, 2023 and 2022, respectively, was as follows (dollars in thousands):

(1) In addition, the Company had $58,116 and $48,740 outstanding in additional letters of credit unrelated to the Credit Facility as of December 31, 2023 and 2022, respectively.

The Company has an unsecured commercial paper note program (the “Commercial Paper Program”) with the maximum aggregate face or principal amount outstanding at any one time not to exceed $500,000,000. Under the terms of the Commercial Paper Program, the Company may issue, from time to time, unsecured commercial paper notes with varying maturities of less than one year. The Commercial Paper Program is backstopped by the Company's commitment to maintain available borrowing capacity under the Credit Facility in an amount equal to actual borrowings under the Commercial Paper Program.

During the year ended December 31, 2023:

•In March 2023, the Company repaid $250,000,000 principal amount of its 2.85% unsecured notes at par at maturity.

•In September 2023, the Company repaid its $150,000,000 Term Loan at par in advance of its February 2024 scheduled maturity.

•In September 2023, the Company utilized $37,600,000 of restricted cash held in a principal reserve fund to repay a portion of the outstanding secured variable rate indebtedness of Avalon Clinton North and Avalon Clinton South.

•In October 2023, in conjunction with the acquisition of Avalon West Plano, the Company assumed a $63,041,000 fixed rate mortgage loan, with a contractual interest rate of 4.18% and an effective interest rate of 5.97%, maturing in May 2029.

•In December 2023, the Company issued $400,000,000 principal amount of unsecured notes in a public offering under its existing shelf registration statement for proceeds net of underwriting fees of approximately $397,156,000, before considering the impact of other offering costs. The notes mature in December 2033 and were issued at a 5.30% interest rate, resulting in a 5.19% effective rate including the impact of issuance costs and hedging activity.

•In December 2023, the Company repaid $350,000,000 principal amount of its 4.20% unsecured notes at par at maturity.

In the aggregate, secured notes payable mature at various dates from March 2027 through July 2066, and are secured by certain apartment communities (with a net carrying value of $1,284,650,000, excluding communities classified as held for sale, as of December 31, 2023).

Scheduled payments and maturities of secured notes payable and unsecured notes outstanding at December 31, 2023 were as follows (dollars in thousands):

The Company's unsecured notes are redeemable at the Company's option, in whole or in part, generally at a redemption price equal to the greater of (i)100% of their principal amount or (ii) the sum of the present value of the remaining scheduled payments of principal and interest discounted at a rate equal to the yield on U.S. Treasury securities with a comparable maturity plus a spread between 10 and 30 basis points depending on the specific series of unsecured notes, plus accrued and unpaid interest to the redemption date.

The Company is subject to financial covenants contained in the Credit Facility and the indentures under which the unsecured notes were issued. The principal financial covenants include the following:

•limitations on the amount of total and secured debt in relation to the Company's overall capital structure;

•limitations on the amount of the Company's unsecured debt relative to the undepreciated basis of real estate assets that are not encumbered by property-specific financing; and

•minimum levels of debt service coverage.

The Company was in compliance with these covenants at December 31, 2023.

4. Equity

As of December 31, 2023 and 2022, the Company's charter had authorized for issuance a total of 280,000,000 shares of common stock and 50,000,000 shares of preferred stock.

During the year ended December 31, 2023, the Company:

i. issued 5,773 shares of common stock in connection with stock options exercised;

ii. issued 3,454 shares of common stock through the Company's dividend reinvestment plan;

iii. issued 153,162 shares of common stock in connection with restricted stock grants and the conversion of performance awards to shares of common stock;

iv. issued 2,000,000 shares of common stock in the settlement of the forward contracts, as discussed below;

v. issued 23,059 shares of common stock through the Employee Stock Purchase Plan;

vi. withheld 62,937 shares of common stock to satisfy employees' tax withholding and other liabilities;

vii. canceled 2,119 shares of restricted common stock upon forfeiture; and

viii. repurchased 11,800 shares of common stock through the Stock Repurchase Program (as defined below).

Deferred compensation granted under the Company's Second Amended and Restated 2009 Equity Incentive Plan (the “Plan”) for the year ended December 31, 2023 does not impact the Company's Consolidated Financial Statements until recognized as compensation cost.

The Company has a continuous equity program (the “CEP”) under which the Company may sell (and/or enter into forward sale agreements for the sale of) up to $1,000,000,000 of its common stock from time to time. Actual sales will depend on a variety of factors to be determined by the Company, including market conditions, the trading price of the Company's common stock and the Company's determinations of the appropriate funding sources. The Company engaged sales agents for the CEP who receive compensation of up to 1.5% of the gross sales price for shares sold. The Company expects that, if entered into, it will physically settle each forward sale agreement on one or more dates specified by the Company on or prior to the maturity date of that particular forward sale agreement, in which case the Company will receive aggregate net cash proceeds at settlement equal to the number of shares underlying the particular forward agreement multiplied by the forward sale price. However, the Company may also elect to cash settle or net share settle a forward sale agreement. In connection with each forward sale agreement, the Company will pay the forward seller, in the form of a reduced initial forward sale price, a commission of up to 1.5% of the sales prices of all borrowed shares of common stock sold. During the years ended December 31, 2023 and 2022, the Company hadno sales under this program. During the year ended December 31, 2021, the Company sold 122,343 shares of common stock at an average sales price of $226.15 per share, for net proceeds of $27,253,000 under this program. In addition, during the year ended December 31, 2022, the Company settled the outstanding forward contracts entered into in December 2021 under this program, selling 68,577 shares of common stock for $229.34 per share and net proceeds of $15,727,000. As of December 31, 2023, the Company had $705,961,000 remaining authorized for issuance under the CEP.

In addition to the CEP, during the year ended December 31, 2023, the Company settled the outstanding forward contracts entered into in April 2022 (the “Equity Forward”), issuing 2,000,000 shares of common stock, net of offering fees and discounts, for $491,912,000 or $245.96 per share.

The Company has a stock repurchase program under which the Company may acquire shares of its common stock in open market or negotiated transactions up to an aggregate purchase price of $500,000,000 (the “Stock Repurchase Program”). Purchases of common stock under the Stock Repurchase Program may be exercised at the Company’s discretion with the timing and number of shares repurchased depending on a variety of factors including price, corporate and regulatory requirements and other corporate liquidity requirements and priorities. The Stock Repurchase Program does not have an expiration date and may be suspended or terminated at any time without prior notice. During the year ended December 31, 2023, the Company repurchased 11,800 shares of common stock at an average price of $161.96 per share. During the years ended December 31, 2022 and 2021, the Company hadno repurchases of shares under this program. As of December 31, 2023, the Company had $314,237,000 remaining authorized for purchase under this program.

5. Investments

Investments in Consolidated Real Estate Entities

Details regarding communities acquired in 2023, 2022 and 2021, are summarized in the following table (dollars in thousands):

(1) In conjunction with the acquisition of Avalon West Plano, the Company assumed a $63,041 fixed rate mortgage loan, with a contractual interest rate of 4.18%, maturing in May 2029.

The Company accounted for these purchases as asset acquisitions and recorded the acquired assets and assumed liabilities, including identifiable intangibles, at their relative fair values based on the purchase price and acquisition costs incurred.

Structured Investment Program

The Company operates a Structured Investment Program (the “SIP”), an investment platform through which the Company provides mezzanine loans or preferred equity to third-party multifamily developers. During the year ended December 31, 2023, the Company entered into four additional commitments, agreeing to provide an aggregate investment of up to $99,210,000 in multifamily development projects. As of December 31, 2023, the Company hadseven commitments to fund up to $191,585,000 in the aggregate. The Company's investment commitments have a weighted average rate of return of 11.5% and have initial maturity dates between September 2025 and December 2027. At December 31, 2023, the Company had funded $96,461,000 of these commitments.

The Company evaluates each SIP commitment to determine the classification as a loan or an investment in a real estate development project. As of December 31, 2023, all of the SIP commitments are classified as loans. The Company includes amounts outstanding under the SIP as a component of prepaid expenses and other assets on the accompanying Consolidated Balance Sheets. The Company evaluates the credit risk for each commitment on an ongoing basis, estimating the reserve for credit losses using relevant available information from internal and external sources. Market-based historical credit loss data provides the basis for the estimation of expected credit losses, with adjustments, if necessary, for differences in current commitment-specific risk characteristics, such as the amount of equity capital provided by a borrower, nature of the real estate being developed or other factors.

For theseven existing commitments, interest is recognized as earned as interest income, and interest income and any change in the expected credit loss are included as a component of income from unconsolidated investments, on the accompanying Consolidated Statements of Comprehensive Income.

Unconsolidated Investments

The Company accounts for its investments in unconsolidated entities under the equity method of accounting or under the measurement alternative, as discussed in Note 1, “Organization, Basis of Presentation and Significant Accounting Policies,” under Principles of Consolidation. As of December 31, 2023, the Company had investments infive unconsolidated entities with real estate entities holdings, with ownership interest percentages ranging from 20.0% to 50.0%, coupled with other unconsolidated investments including property technology and environmentally focused companies and investment management funds. Forone of the investments which owns an apartment community that is under development and in which the Company has an investment of 25.0%, the Company has guaranteed a construction loan on behalf of the venture, which had an outstanding balance of $135,983,000 as of December 31, 2023. Any amounts under the guarantee of this construction loan are obligations of the venture partners in proportion to their ownership interest. The significant accounting policies of the Company's unconsolidated investments are consistent with those of the Company in all material respects. Certain of these investments are subject to various buy‑sell provisions or other rights which are customary in real estate joint venture agreements. The Company and its partners in these entities may initiate these provisions to either sell the Company's interest or acquire the interest from the Company's partner. The Company is responsible for the day-to-day operations of the unconsolidated communities below and is the management agent subject to the terms of management agreements for all communities except for Brandywine Apartments of Maryland, LLC, which is managed by a third party.

The following presents the Company's activities in unconsolidated investments for the years ended December 31, 2023, 2022 and 2021:

Archstone Multifamily Partners AC LP (the “U.S. Fund”)—The Company acquired its interest in the U.S. Fund as part of the Archstone Acquisition in 2013 (as defined in Note 5, “Investments in Real Estate Entities,” of the Consolidated Financial Statements in Item 8 in the Company's Form 10-K filed February 22, 2019). The Company was the general partner of the U.S. Fund and had a 28.6% combined general partner and limited partner equity interest. During 2022, the U.S. Fund sold its final three communities and the Company's proportionate share of the gains in accordance with GAAP was $38,144,000. In conjunction with achieving a threshold return under provisions of the U.S. Fund, the Company received incentive distributions for its promoted interest. During the years ended December 31, 2023 and 2022, the Company recognized income of $1,519,000 and $4,690,000, respectively, for its promoted interest, which is included in income from unconsolidated investments on the accompanying Consolidated Statements of Comprehensive Income. During 2023, the Company completed the dissolution of the U.S. Fund.

Archstone Multifamily Partners AC JV LP (the “AC JV”)—The Company had a 20.0% equity interest in the AC JV, and acquired its interest as part of the Archstone Acquisition in 2013. During 2021, the AC JV sold its finaltwo communities and the Company's proportionate share of the gains in accordance with GAAP was $23,305,000. During 2022, the Company completed the dissolution of the AC JV.

Legacy JV—As part of the Archstone Acquisition the Company entered into a limited liability company agreement with Equity Residential, through which it assumed obligations of Archstone in the form of preferred interests, some of which are governed by tax protection arrangements (the “Legacy JV”). The Company has a 40.0% interest in the Legacy JV. During the years ended December 31, 2023, 2022 and 2021, the Legacy JV redeemed certain of the preferred interests and paid accrued dividends, for which the Company contributed $940,000, $860,000 and $1,340,000, respectively. At December 31, 2023, the remaining preferred interests had an aggregate liquidation value of $34,124,000, the Company's 40.0% share of which was included in accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets.

NYTA MF Investors LLC (“NYC Joint Venture”)—During 2018, the Company contributed five wholly-owned communities containing an aggregate of 1,301 apartment homes and 58,000 square feet of commercial space, located in New York City, NY, to a newly formed joint venture with the intent to own and operate the communities. The Company retained a 20.0% equity interest in the venture with the partners sharing in returns in accordance with their ownership interests. NYC Joint Venture has outstanding $394,734,000 fixed rate mortgage loans that are payable by the venture. The Company has not guaranteed the debt of NYC Joint Venture, nor does the Company have any obligation to fund this debt should NYC Joint Venture be unable to do so. At December 31, 2023, the Company has an equity investment of $55,695,000 (net of distributions).

MVP I, LLC—During 2004, the Company entered into a joint venture agreement with an unrelated third-party to develop Avalon at Mission Bay II, an apartment community located in San Francisco, CA, which completed construction during 2006 and contains 313 apartment homes. The Company has a 25.0% equity interest in the venture. MVP I, LLC has an outstanding $103,000,000 fixed rate mortgage loan that is payable by the venture. The Company has not guaranteed the debt of MVP I, LLC, nor does the Company have any obligation to fund this debt should MVP I, LLC be unable to do so. The Company has fully recovered its basis as of December 31, 2023.

Brandywine Apartments of Maryland, LLC (“Brandywine”)—The Company acquired its interest in Brandywine as part of the Archstone Acquisition. Brandywine owns a 305 apartment home community located in Washington, D.C. Brandywine is comprised offive members who hold various interests in the joint venture, with the Company having a 28.7% equity interest in Brandywine. Brandywine had an outstanding $19,062,000 fixed rate mortgage loan that is payable by the venture. The Company has not guaranteed the debt of Brandywine, nor does the Company have any obligation to fund this debt should Brandywine be unable to do so. At December 31, 2023, the Company had an equity investment of $14,602,000 (net of distributions) in Brandywine.

Avalon Alderwood MF Member, LLC—During 2019, the Company entered into a joint venture to develop, own, and operate Avalon Alderwood Place, an apartment community located in Lynnwood, WA, which completed construction during 2022 and contains 328 apartment homes. The Company has a 50.0% interest in the venture and, as of December 31, 2023, the Company has a total equity investment of $53,638,000. The venture is a VIE, though the Company is not the primary beneficiary because it shares control with its venture partner. The Company and its venture partner share decision making authority for all significant aspects of the venture's activities including, but not limited to, changes in the ownership or capital structure, and the operating budget.

Arts District Joint Venture—During 2020, the Company entered into a joint venture to develop, own, and operate AVA Arts District, an apartment community located in Los Angeles, CA, which is currently under construction and expected to contain 475 apartment homes (unaudited) and 56,000 square feet (unaudited) of commercial space when completed. As of

December 31, 2023, the Company has a 25.0% interest in the venture, and excluding costs incurred in excess of equity in the underlying net assets of the venture, has an equity investment of $32,738,000. The remaining development costs are primarily expected to be funded by the venture's variable rate construction loan. The venture has drawn $135,983,000 of $167,147,000 maximum borrowing capacity of the construction loan as of December 31, 2023. While the Company guarantees the construction loan on behalf of the venture, any amounts payable under the guarantee are obligations of the venture partners in proportion to ownership interest. The venture is an unconsolidated VIE as the Company is not the primary beneficiary due to shared control and decision making with its venture partner. The Company and its venture partner share decision making authority for all significant aspects of the venture's activities including, but not limited to, changes in the ownership, changes to the development plan or budget, and major operating decisions including annual business plans.

Property Technology and Environmental Investments—The Company has invested $46,926,000 in various property technology and environmentally focused companies directly and indirectly through investment management funds. The Company’s interest in each individual investment represents less than 10% of the respective venture's equity interests. In addition, as of December 31, 2023, the Company has $73,892,000 in outstanding equity commitments, with the timing and amount for these commitments to be fulfilled dependent on if, and when, investment opportunities are identified by the respective funds. During the years ended December 31, 2023, 2022 and 2021, the Company recognized income and unrealized gains of $4,161,000, $8,315,000 and $15,908,000, respectively, related to these investments, which was reported as a component of income from unconsolidated investments on the accompanying Consolidated Statements of Comprehensive Income.

6. Real Estate Disposition Activities

Details regarding the real estate sales, which resulted in a gain in accordance with GAAP of $287,424,000, excluding for-sale residential condominiums at The Park Loggia, are summarized in the following table (dollars in thousands):

As of December 31, 2023, the Company hadno real estate assets that qualified as held for sale.

The Park Loggia

The Park Loggia, located in New York, NY, contains 172 for-sale residential condominiums and 66,000 square feet of commercial space. The Company soldsix,40 and 53 residential condominiums at The Park Loggia, for gross proceeds of $25,387,000, $126,848,000 and $135,458,000 resulting in a loss in accordance with GAAP of $73,000 and gain in accordance with GAAP of $2,217,000 and $3,110,000 during the years ended December 31, 2023, 2022 and 2021, respectively. The Company incurred $389,000, $2,129,000 and $4,087,000 during the years ended December 31, 2023, 2022 and 2021, respectively, in marketing, operating and administrative costs. All amounts are included in other real estate activity on the accompanying Consolidated Statements of Comprehensive Income. As of December 31, 2023, there weretwo residential condominiums remaining to be sold. As of December 31, 2023 and 2022, the unsold for-sale residential condominiums at The Park Loggia had an aggregate carrying value of $6,603,000 and $32,532,000, respectively, presented in prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.

7. Commitments and Contingencies

Employment Agreements and Arrangements

At December 31, 2023, the Company has an employment agreement with Benjamin W. Schall, who joined the Company on January 25, 2021 as President and a member of the Board of Directors, and was appointed to the additional role of Chief Executive Officer effective January 3, 2022. The employment agreement expires on January 25, 2024, although provisions relating to equity awards granted during the term of the employment agreement continue to apply with respect to those awards.

The standard restricted stock, option and performance award agreements used by the Company in its compensation program provide that upon an employee's termination without cause or the employee's Retirement (as defined in the agreement), (i) all outstanding stock options and restricted shares of stock held by the employee will vest, and the employee will have up to 12 months or until the fifth anniversary of the grant date, if later, or until the option expiration date, if earlier, to exercise any options then held and (ii) a pro rata share (based on the portion of the performance period that has been completed) of performance awards that have completed at least one year of their performance period shall vest, with settlement to occur at the end of the performance period in accordance with achievement thereunder. Under the agreements, Retirement generally means a termination of employment and other business relationships, other than for cause, after attainment of age 50, provided certain conditions are met, including that (i) the employee has worked for the Company for at least 10 years, (ii) the employee's age at Retirement plus years of employment with the Company equals at least 70 and (iii) the employee provides at leastsix months written notice of intent to retire.

If a sale event (as defined) of the Company occurs, all outstanding multiyear performance awards will vest at their target value and are settled. The Company also has an Officer Severance Program (the “Program”). Under the Program, in the event an officer who is not otherwise covered by a severance arrangement is terminated (other than for cause), or chooses to terminate his or her employment for good reason (as defined), in either case in connection with or within 24 months following a sale event (as defined) of the Company, such officer will generally receive a cash lump sum payment equal to a multiple of the officer's covered compensation (base salary plus annual cash bonus). The multiple isone time for vice presidents and senior vice presidents, two times for executive vice presidents andthree times for the chief executive officer. The officer's restricted stock, options and performance awards would also vest. Costs related to the Program are deferred and recognized over the requisite service period when considered by management to be probable and estimable.

Legal Contingencies

The Company recognizes a loss associated with contingent legal matters when the loss is probable and estimable.

In 2022 and early 2023, the Company was named as a defendant in cases brought by private litigants alleging antitrust violations by RealPage, Inc. and owners and/or operators of multifamily housing which utilize revenue management systems provided by RealPage, Inc. The Company engaged with the plaintiffs' counsel to explain why it believed that these cases were without merit as they pertained to the Company. Following these discussions, the plaintiffs filed a notice of voluntary dismissal in July 2023, which resulted in the Company being dismissed without prejudice from these cases. Subsequently, on November 1, 2023, the District of Columbia filed a lawsuit in the Superior Court of the District of Columbia against RealPage, Inc. and 14 owners and/or operators of multifamily housing in the District of Columbia, including the Company, alleging that the defendants violated the District of Columbia Antitrust Act by unlawfully agreeing to use RealPage, Inc. revenue management systems and sharing sensitive data. The Company intends to vigorously defend against this lawsuit. Given the early stage of the District of Columbia’s lawsuit, the Company is unable to predict the outcome or estimate the amount of loss, if any, that may result from the lawsuit.

The Company is involved in various other claims and/or administrative proceedings that arise in the ordinary course of its business. While no assurances can be given, the Company does not currently believe that any of these other outstanding litigation matters, individually or in the aggregate, will have a material adverse effect on its financial condition or results of operations.

In addition, the Company accounts for recoveries from legal matters as a reduction in the legal and related costs incurred associated with the matter, with recoveries in excess of these costs reported as a gain or, where appropriate, a reduction in the net cost basis of a community to which the suit related. During the year ended December 31, 2022, the Company recognized $6,000,000 in legal settlement proceeds related to a construction defect at a community, reported as a component of general and administrative expense on the accompanying Consolidated Statements of Comprehensive Income. There wereno material receipts during the years ended December 31, 2023 and 2021.

Lease Obligations

The Company owns seven apartment communities andtwo commercial properties, located on land subject to ground leases expiring between July 2046 and April 2106. The Company has purchase options for all ground leases expiring prior to 2062. The ground leases forsix of theseven apartment communities and thetwo commercial properties, are operating leases, with rental expense recognized on a straight-line basis over the lease term. In addition, the Company is party to 15 leases for its corporate and regional offices with varying terms through 2031, all of which are operating leases.

As of December 31, 2023 and 2022, the Company had total operating lease assets of $106,146,000 and $114,977,000, respectively, and lease obligations of $133,220,000 and $142,602,000, respectively, reported as components ofright of use lease assets andlease liabilities, respectively, on the accompanying Consolidated Balance Sheets. The Company incurred costs of $16,342,000, $15,667,000 and $15,458,000 for the years ended December 31, 2023, 2022 and 2021, respectively, related to operating leases.

The Company hasone apartment community located on land subject to a ground lease andfour leases for portions of parking garages adjacent to apartment communities, that are finance leases. As of December 31, 2023 and 2022, the Company had total finance lease assets of $28,528,000 and $28,354,000, respectively, and total finance lease obligations of $20,012,000 and $20,069,000, respectively, reported as components ofright of use lease assets andlease liabilities on the accompanying Consolidated Balance Sheets.

The following table details the weighted average remaining lease term and discount rates for the Company’s ground and office leases:

(1) Excludestwo leases that have been executed but for which the Company has not yet taken control.

The following table details the future minimum payments of the Company's current leases as of December 31, 2023 (dollars in thousands):

(1) Includestwo leases that have been executed but for which the Company has not yet taken control.

8. Segment Reporting

The Company's reportable operating segments include Same Store, Other Stabilized and Development/Redevelopment. Annually as of January 1, the Company determines which of its communities fall into each of these categories and generally maintains that classification throughout the year for the purpose of reporting segment operations, unless disposition or redevelopment plans regarding a community change.

•Same Store is composed of consolidated communities where a comparison of operating results from the prior year to the current year is meaningful as these communities were owned and had stabilized occupancy as of the beginning of the respective prior year. For the year ended December 31, 2023, Same Store communities are consolidated for financial reporting purposes, had stabilized occupancy as of January 1, 2022, are not conducting or are not probable to conduct substantial redevelopment activities and are not held for sale as of December 31, 2023 or probable for disposition to unrelated third parties within the fiscal year. A community is considered to have stabilized occupancy at the earlier of (i) attainment of 90% physical occupancy or (ii) theone year anniversary of completion of development or redevelopment.

•Other Stabilizedis composed of completed consolidated communities that the Company owns and that are not Same Store but that had stabilized occupancy, as defined above, as of January 1, 2023, or which were acquired during the years ended December 31, 2023 or 2022. Other Stabilized excludes communities that are conducting or are probable to conduct substantial redevelopment activities within the fiscal year.

•Development/Redevelopmentis composed of (i) consolidated communities that are either currently under construction, or were under construction during the fiscal year, which may be partially or fully complete and operating, (ii) consolidated communities where substantial redevelopment is in progress or is probable to begin during the fiscal year and (iii) communities that have been complete for less than one year and did not have stabilized occupancy, as defined above, as of January 1, 2023.

In addition, the Company owns land for future development and has other corporate assets that are not allocated to an operating segment.

The Company's segment disclosures present the measure(s) used by the CODM for assessing each segment's performance. The Company's CODM is comprised of several members of its executive management team who use net operating income (“NOI”) as the primary financial measure for Same Store communities and Other Stabilized communities. NOI is defined by the Company as total property revenue less direct property operating expenses (including property taxes), and excluding corporate-level income (including management, development and other fees), corporate-level property management and other indirect operating expenses, expensed transaction, development and other pursuit costs, net of recoveries, interest expense, net, loss on extinguishment of debt, net, general and administrative expense, income from unconsolidated investments, depreciation expense, income tax expense, casualty loss, gain on sale of communities, other real estate activity, and net operating income from real estate assets sold or held for sale. The CODM evaluates the Company's financial performance on a consolidated residential and commercial basis. The commercial results attributable to the non-apartment components of the Company's mixed-use communities and other nonresidential operations represent 1.8%,2.0% and 1.7% of total NOI for the years ended December 31, 2023, 2022 and 2021, respectively. Although the Company considers NOI a useful measure of a community's or communities' operating performance, NOI should not be considered an alternative to net income or net cash flow from operating activities, as determined in accordance with GAAP. NOI excludes a number of income and expense categories as detailed in the reconciliation of NOI to net income.

A reconciliation of NOI to net income for years ended December 31, 2023, 2022 and 2021 is as follows (dollars in thousands):

The following is a summary of NOI from real estate assets sold or held for sale for the periods presented (dollars in thousands):

The primary performance measure for communities under development or redevelopment depends on the stage of completion. While under development, management monitors actual construction costs against budgeted costs as well as lease-up pace and rent levels compared to budget.

The following table details the Company's segment information as of the dates specified (dollars in thousands). The segments are classified based on the individual community's status at December 31, 2023 for the years ended December 31, 2023 and 2022 and at December 31, 2022, for the year ended December 31, 2021. Segment information for the years ended December 31, 2023, 2022 and 2021 has been adjusted to exclude the real estate assets that were sold from January 1, 2021 through December 31, 2023, or otherwise qualify as held for sale as of December 31, 2023, as described in Note 6, “Real Estate Disposition Activities.”

(1) Does not include gross real estate either sold or classified as held for sale subsequent to December 31, 2022 and 2021 of $280,889 and $760,990, respectively.

(2) Gross real estate for the Company's Same Store includes capitalized additions of approximately $188,507, $209,607 and $158,991 in 2023, 2022 and 2021, respectively.

(3) Revenue represents third-party property management, developer fees and miscellaneous income and other ancillary items which are not allocated to a reportable segment. Gross real estate includes the for-sale residential condominiums at The Park Loggia, as discussed in Note 6, “Real Estate Disposition Activities.”

(4) Communities in Same Store Other Expansion Regions were included in Other Stabilized for the year ended December 31, 2021.

9. Stock-Based Compensation Plans

The Company's Plan includes an authorization to issue shares of the Company's common stock, par value $0.01 per share. At December 31, 2023, the Company had 5,424,356 shares remaining available to issue under the Plan, exclusive of shares that may be issued to satisfy currently outstanding awards such as stock options or performance awards. The Plan provides for equity awards to associates, officers, non-employee directors and other key personnel of the Company and its subsidiaries in the form of restricted stock, restricted stock units, stock options that qualify as incentive stock options (“ISOs”) under Section 422 of the Code, non-qualified stock options, stock appreciation rights and performance awards, among others. No grants of stock options and other awards will be made after May 15, 2027, and no grants of incentive stock options will be made after February 16, 2027.

The Company's share-based compensation framework includes annual restricted stock awards and multi-year performance awards (the “Performance Awards”). The annual restricted stock vests over a three-year period at one-third per year. For annual restricted stock awards, in lieu of restricted stock, an officer may elect to receive up to 100% of the award value, in increments of 25%, in the form of stock options, which vests consistent with the restricted stock awards. Annually, the Company grants a target number of performance awards, with the ultimate award determined by the total shareholder return of the Company's common stock and/or operating performance metrics, measured over a performance period ofthree years. Performance units earned at the end of the measurement period are settled in fully vested shares of common stock and a payment of a cash amount representing accrued dividends on earned performance awards. The Company granted supplemental stock options in February 2021, that have aten-year term and cliff vested on March 1, 2023. The options were granted at an exercise price that equaled the closing stock price on the grant date with recipients having 12 months to exercise the option if terminated without cause, and will have until the expiration date to exercise the options if they retire.

For Performance Awards, after the first year of the performance period, if an employee's employment terminates on account of death, disability, retirement, or termination without cause, the employee's target grant will be pro-rated based on the employee's service time during the performance period. The final payout is based on actual performance, at which time the units will be converted into shares and a payment of a cash amount for accrued dividends based on actual performance. For other terminating events, performance awards are generally forfeited.

Information with respect to stock options granted under the Plan is as follows:

(1)Includes 4,847 options from recipient elections to receive a portion of earned restricted stock awards in the form of stock options.

(2)All options are from recipient elections to receive a portion of earned restricted stock awards in the form of stock options.

The Company used the Black-Scholes Option Pricing model to determine the grant date fair value of options. The assumptions used are as follows:

The following summarizes the exercise prices and contractual lives of options outstanding as of December 31, 2023:

Options outstanding at December 31, 2023 had an intrinsic value of $2,068,000. Options exercisable had an intrinsic value of $1,909,000 and had a weighted average contractual life of 7.2 years. The intrinsic value of options exercised under the Plan during 2023, 2022 and 2021 was $113,000, $602,000 and $186,000, respectively.

Information with respect to performance awards granted is as follows:

(1) The shares of common stock earned was based on the total shareholder return metrics for the Company’s common stock for 69,064 performance awards and financial metrics related to operating performance, net asset value and leverage metrics of the Company for 68,969 performance awards.

(2) Represents the change in the number of performance awards earned based on performance achievement.

(3) The shares of common stock that may be earned is based on the total shareholder return metrics for the Company’s common stock for 39,972 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 32,811 performance awards.

(4) The shares of common stock that may be earned is based on the total shareholder return metrics for the Company’s common stock for 49,611 performance awards and financial metrics related to operating performance and leverage metrics of the Company for 40,604 performance awards.

The Company used a Monte Carlo model to assess the compensation cost associated with the portion of the performance awards granted for which achievement will be determined by using total shareholder return measures. The assumptions used are as follows:

(1) Estimated volatility over the life of the plan is using 50% historical volatility and 50% implied volatility.

For the portion of the performance awards granted for which achievement will be determined by using financial metrics, the compensation cost was based on an average grant date value of $177.83, $233.94 and $178.38, for the years ended December 31, 2023, 2022 and 2021, respectively, and the Company's estimate of corporate achievement for the financial metrics.

Information with respect to restricted stock granted is as follows:

Total employee stock-based compensation cost recognized in income was $27,417,000, $34,131,000 and $25,100,000 for the years ended December 31, 2023, 2022 and 2021, respectively, and total capitalized stock-based compensation cost was $10,906,000, $10,431,000 and $9,472,000 for the years ended December 31, 2023, 2022 and 2021, respectively. At December 31, 2023, there was a total unrecognized compensation cost of $28,204,000 for unvested restricted stock, stock options and performance awards, which is expected to be recognized over a weighted average period of 1.8 years. Forfeitures are included in compensation cost as they occur.

Employee Stock Purchase Plan

In October 1996, the Company adopted the 1996 Non-Qualified Employee Stock Purchase Plan (as amended, the “ESPP”). Initially,1,000,000 shares of common stock were reserved for issuance, and as of December 31, 2023, there are 569,016 shares remaining available for issuance under the ESPP. Employees of the Company generally are eligible to participate in the ESPP if, as of the last day of the applicable purchase period, they have been employed by the Company for at leastone calendar month. Under the ESPP, eligible employees can acquire shares of the Company's common stock through payroll deductions, subject to maximum purchase limitations, duringtwo purchase periods. The first purchase period begins January 1 and ends June 10, and the second purchase period begins July 1 and ends December 10. The purchase price for common stock under the plan is 85% of the lesser of the fair market value of the Company's common stock on the first or the last day of the applicable purchase period. The offering dates, purchase dates and duration of purchase periods may be changed if the change is announced prior to the beginning of the affected date or purchase period. The Company issued 23,059,20,837 and 21,362 shares and recognized compensation expense of $911,000, $564,000 and $1,609,000 under the ESPP for the years ended December 31, 2023, 2022 and 2021, respectively. The Company accounts for transactions under the ESPP using the fair value method prescribed by accounting guidance applicable to entities that use employee share purchase plans.

10. Related Party Arrangements

Unconsolidated Entities

The Company manages unconsolidated real estate entities and may provide other real estate related services to third parties, for which it receives asset management, property management, construction, development and redevelopment fee revenue. From these entities, the Company earned fees of $7,722,000, $6,333,000 and $3,084,000 for the years ended December 31, 2023, 2022 and 2021, respectively. In addition, the Company had outstanding receivables associated with its property and construction management roles of $7,946,000 and $2,855,000 as of December 31, 2023 and 2022, respectively.

Director Compensation

Directors of the Company who are also employees receive no additional compensation for their services as a director. Following each annual meeting of stockholders, non-employee directors receive (i) a number of shares of restricted stock (or deferred stock units) having a value of $175,000 and (ii) a cash payment of $100,000, payable in equal quarterly installments of

$25,000. The number of shares of restricted stock (or deferred stock units) is calculated based on the closing price on the day of the award. Non-employee directors may elect to receive all or a portion of cash payments in the form of deferred stock units. Additionally, the non-Executive Chairman receives an additional annual fee of $250,000 payable in equal quarterly installments of $62,500, the Lead Independent Director receives in the aggregate an additional annual fee of $35,000 payable in equal quarterly installments of $8,750, the non-employee director serving as the chairperson of the Audit Committee receives an additional annual fee of $30,000 per year payable in equal quarterly installments of $7,500, the non-employee director serving as the chairperson of the Compensation Committee receives an additional annual fee of $25,000 per year payable in equal quarterly installments of $6,250 and the Nominating, Governance and Corporate Responsibility and Investment and Finance Committee chairpersons receive an additional annual fee of $20,000 payable in equal quarterly installments of $5,000.

The Company recorded non-employee director compensation expense relating to restricted stock grants and deferred stock units in the amount of $2,446,000, $2,228,000 and $1,981,000 for the years ended December 31, 2023, 2022 and 2021, respectively, as a component of general and administrative expense. Deferred compensation relating to these restricted stock grants and deferred stock units to non-employee directors was $799,000, $794,000 and $696,000 on December 31, 2023, 2022 and 2021, respectively, reported as a component of prepaid expenses and other assets on the accompanying Consolidated Balance Sheets.

11. Fair Value

Financial Instruments Carried at Fair Value

Derivative Financial Instruments

The Company uses Hedging Derivatives to manage its interest rate risk. These instruments are carried at fair value in the Company's financial statements. The Company minimizes its credit risk on these transactions by dealing with major, creditworthy financial institutions which have an A or better credit rating by the Standard & Poor's Ratings Group or equivalent, and monitors the credit ratings of counterparties and the exposure of the Company to any single entity. The Company believes the likelihood of realizing losses from counterparty nonperformance is remote. 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, such as interest rate, term to maturity and volatility, the credit valuation adjustments associated with its derivatives use Level 3 inputs, such as estimates of current credit spreads, which the Company concluded are not significant. As a result, the Company has determined that its derivative valuations are classified in Level 2 of the fair value hierarchy.

The following table summarizes the consolidated derivative positions at December 31, 2023 (dollars in thousands):

(1) For debt hedged by interest rate caps, represents the weighted average interest rate on the hedged debt prior to any impact of the associated interest rate caps.

The following derivative activity occurred during the year ended December 31, 2023:

•In connection with the issuance of the Company's $400,000,000 unsecured notes in December 2023 maturing in 2033, the Company terminated $250,000,000 of forward interest rate swap agreements designated as cash flow hedges of the interest rate variability on the issuance of unsecured notes, receiving payments of $8,331,000 which will be recognized over the life of the unsecured notes as a reduction in the effective interest rate. All of the positions settled by the Company were forward interest rate swaps that the Company had entered into during 2023. The Company has deferred these gains in accumulated other comprehensive income on the accompanying Consolidated Balance Sheets, and is recognizing the impact as a component of interest expense, net, over the term of the respective hedged debt.

•In addition, the Company entered into $200,000,000 of forward interest rate swap agreements to reduce the impact of variability in interest rates on a portion of the Company's anticipated future debt issuance activity in 2024. The

Company expects to cash settle the swaps and either pay or receive cash for the then current fair value. Assuming that the Company issues the debt as expected, the hedging impact from these positions will then be recognized over the life of the issued debt as a yield adjustment.

The Company had certain derivatives not designated as hedges during the years ended December 31, 2023, 2022 and 2021, for which fair value changes during each of the respective years were not material.

Cash flow hedge losses reclassified from accumulated other comprehensive income into earnings were $1,360,000, $3,883,000 and $13,151,000 for the year ended December 31, 2023, 2022 and 2021, respectively.

The Company anticipates reclassifying approximately $582,000 of net hedging losses from accumulated other comprehensive income into earnings within the next 12 months as an offset to the hedged item during this period.

Redeemable Noncontrolling Interests

During the year ended December 31, 2023,7,500 DownREIT units were redeemed for cash by the Company in conjunction with the sale of Avalon at Newton Highlands. Under the DownREIT agreement, for each limited partnership unit, the limited partner was entitled to receive cash in the amount equal to the fair value of the Company's common stock on or about the date of redemption. The limited partnership units in the DownREIT were valued using the market price of the Company's common stock, a Level 1 price under the fair value hierarchy.

Equity Securities

The Company has direct equity investments in property technology and environmentally focused companies. These investments are accounted for using the measurement alternative and are valued at the market price of observable transactions.

Financial Instruments Not Carried at Fair Value

Cash, Cash Equivalents and Restricted Cash

Cash, cash equivalent and restricted cash balances are held with various financial institutions within accounts designed to preserve principal. The Company monitors credit ratings of these financial institutions and the concentration of cash, cash equivalent and restricted cash balances with any one financial institution and believes the likelihood of realizing material losses related to cash, cash equivalent and restricted cash balances is remote. Cash, cash equivalent and restricted cash are carried at their face amounts, which reasonably approximate their fair values and are Level 1 within the fair value hierarchy.

Other Financial Instruments

Rents and other receivables and prepaid expenses, accounts and construction payable and accrued expenses and other liabilities are carried at their face amounts, which reasonably approximate their fair values. The Company determined that its notes receivables approximate fair value, because interest rates, yields and other terms are consistent with interest rates, yields and other terms currently available for similar instruments and are considered to be a Level 2 price within the fair value hierarchy.

Indebtedness

The Company values its fixed rate unsecured notes using quoted market prices, a Level 1 price within the fair value hierarchy. The Company values its mortgage notes payable, variable rate unsecured notes, including the Term Loan, and any outstanding amounts under the Credit Facility and Commercial Paper Program using a discounted cash flow analysis on the expected cash flows of each instrument. This analysis reflects the contractual terms of the instrument, including the period to maturity, and uses observable market-based inputs, including interest rate curves. The process also considers credit valuation adjustments to appropriately reflect the Company's nonperformance risk. The Company has concluded that the value of its mortgage notes payable, variable rate unsecured notes, Term Loan and any outstanding amounts under the Credit Facility and Commercial Paper Program are Level 2 prices as the majority of the inputs used to value its positions fall within Level 2 of the fair value hierarchy.

Financial Instruments Measured/Disclosed at Fair Value on a Recurring Basis

The following tables summarize the classification between the three levels of the fair value hierarchy of the Company's financial instruments measured/disclosed at fair value on a recurring basis (dollars in thousands):

12. Subsequent Events

The Company has evaluated subsequent events, through the date on which this Form 10-K was filed, the date on which these financial statements were issued, and did not identify any items for disclosure.