<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-06-28</periodOfReport>

    <notSubjectToSection16>true</notSubjectToSection16>

    <issuer>
        <issuerCik>0001820877</issuerCik>
        <issuerName>Apartment Income REIT Corp.</issuerName>
        <issuerTradingSymbol>AIRC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188274</rptOwnerCik>
            <rptOwnerName>KELTNER THOMAS L.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4582 S. ULSTER STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1700</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80237</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-06-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>60118</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>39.12</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On June 28, 2024, the Issuer was acquired by Apex Purchaser LLC, Aries Purchaser LLC and Astro Purchaser LLC (collectively, the &quot;Parent Entities&quot;), pursuant to that certain Agreement and Plan of Merger entered into by and among the Issuer, the Parent Entities and Astro Merger Sub, Inc., a wholly owned subsidiary of the Parent Entities and an affiliate of Blackstone Real Estate Partners X L.P. (&quot;Merger Sub&quot;), dated as of April 7, 2024 (the &quot;Merger Agreement&quot;).  Pursuant to the terms of the Merger Agreement, Merger Sub merged with and into the Issuer, with the Issuer surviving such merger as a wholly-owned subsidiary of the Parent Entities (the &quot;Merger&quot;).</footnote>
        <footnote id="F2">At the effective time of the Merger (the &quot;Effective Time&quot;), each share of the Issuer's Class A common stock outstanding immediately prior to the Effective Time (other than certain excluded shares) was automatically canceled and converted into the right to receive $39.12 in cash, without interest and subject to any required withholding taxes.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Thomas L. Keltner</signatureName>
        <signatureDate>2024-07-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
