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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-02-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000731766</issuerCik>
        <issuerName>UNITEDHEALTH GROUP INC</issuerName>
        <issuerTradingSymbol>UNH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002025275</rptOwnerCik>
            <rptOwnerName>Zaetta Christopher R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNITEDHEALTH GROUP INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>1 HEALTH DRIVE</rptOwnerStreet2>
            <rptOwnerCity>EDEN PRAIRIE</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55344</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; Chief Legal Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>176.756</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>523.51</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7226.747</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Faraz A. Choudhry, Attorney-in-Fact for Christopher R. Zaetta</signatureName>
        <signatureDate>2025-02-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2025-02-14
0
0000731766
UNITEDHEALTH GROUP INC
UNH
0002025275
Zaetta Christopher R
C/O UNITEDHEALTH GROUP INCORPORATED
1 HEALTH DRIVE
EDEN PRAIRIE
MN
55344
0
1
0
0
EVP & Chief Legal Officer
0
Common Stock
2025-02-14
4
F
0
176.756
523.51
D
7226.747
D
Faraz A. Choudhry, Attorney-in-Fact for Christopher R. Zaetta
2025-02-18