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

    <schemaVersion>X0607</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2026-02-17</periodOfReport>

    <dateOfOriginalSubmission>2026-03-04</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000877860</issuerCik>
        <issuerName>NATIONAL HEALTH INVESTORS INC</issuerName>
        <issuerTradingSymbol>NHI</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002115811</rptOwnerCik>
            <rptOwnerName>Blankenship Elizabeth Jackson</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>222 ROBERT ROSE DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MURFREESBORO</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>37129</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP, Legal Affairs</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy) 2025</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>73.34</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2025-03-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2030-03-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8333</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy) 2025</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>73.34</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2026-03-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2030-03-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8333</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy) 2025</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>73.34</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2027-03-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2030-03-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8334</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects a stock option grant that was inadvertently omitted from the original Form 3.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kimberly V. Ouimet, by limited power of attorney</signatureName>
        <signatureDate>2026-03-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
