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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-01-28</periodOfReport>

    <issuer>
        <issuerCik>0000922864</issuerCik>
        <issuerName>APARTMENT INVESTMENT &amp; MANAGEMENT CO</issuerName>
        <issuerTradingSymbol>AIV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001229384</rptOwnerCik>
            <rptOwnerName>CONSIDINE TERRY</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>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>180879</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33998</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>LTIP Units of AIMCO Properties, L.P.</value>
                <footnoteId id="F7"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F8"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>32755</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F8"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F9"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F10"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Partnership Common Units</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>32755</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>32755</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Taking into account the transactions reported on this form, Mr. Considine has an overall equity stake in the company of 5,708,126 shares, partnership units, and options, the details of which are more fully described in footnotes 2, 3, 4, and 5 below.</footnote>
        <footnote id="F2">Taking into account the transactions reported on this form, in addition to the reporting person's overall equity stake in the company, 166,660 shares are held by a tax exempt organization under 501(c)(3) of the Internal Revenue Code, for which the reporting person disclaims beneficial ownership.</footnote>
        <footnote id="F3">In addition to the 180,879  shares held directly, the reporting person holds 2,439,557 common partnership units and equivalents in AIMCO Properties, L.P. (&quot;OP Units&quot;).  The 2,439,557 OP Units include 510,452 OP Units held directly by the reporting person, 179,735 OP Units held by an entity in which the reporting person has sole voting and investment power, 1,591,672 OP Units held by Titahotwo Limited Partnership RLLLP (&quot;Titahotwo&quot;), a registered limited liability limited partnership for which the reporting person serves as the general partner and holds a 0.5% ownership interest, and 157,698 OP Units held by the reporting person's spouse, for which the reporting person disclaims beneficial ownership except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F4">In addition to the 180,879 shares held directly, the reporting person holds 2,304,378 unvested partnership units, the vesting of which are subject to certain performance criteria.   Upon conclusion of the performance period and depending on the results thereof, the reporting person may vest in all, some or none of the performance-based partnership units</footnote>
        <footnote id="F5">In addition to the 180,879 shares held directly, the reporting person holds 750,557 stock options, 686,948 of which are vested and exercisable.</footnote>
        <footnote id="F6">Held by the reporting person's spouse, for which the reporting person disclaims beneficial ownership except to the extent of his pecuniary interest therein.</footnote>
        <footnote id="F7">Pursuant to the Fifth Amended and Restated Agreement of Limited Partnership of AIMCO Properties, L.P. (the &quot;Partnership Agreement&quot;), a holder of LTIP Units has the right to convert all or a portion of such holder's vested LTIP Units into Partnership Common Units (as such term is defined in the Partnership Agreement).  Pursuant to the Partnership Agreement, holders of Partnership Common Units have the right to require AIMCO Properties, L.P. to redeem such holder's Partnership Common Units, which redemption may be for Class A Common Stock of Apartment Investment and Management Company or a cash amount equal to the value of such shares of Class A Common Stock pursuant to the formula set forth in the Partnership Agreement.  The form of currency upon redemption is determined in the sole discretion of the general partner of AIMCO Properties, L.P.</footnote>
        <footnote id="F8">Equity Award approved by Compensation and Human Resources Committee in connection with a portion of 2017 long term incentive compensation, price column not applicable.  Receipt of the LTIP Units was subject to satisfaction of total shareholder return criteria over the period compared to specified indices.</footnote>
        <footnote id="F9">The LTIP Units vest 50% on January 31, 2020, and 50% on January 31, 2021.</footnote>
        <footnote id="F10">The LTIP Units do not expire.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Terry Considine</signatureName>
        <signatureDate>2020-01-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
