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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2023-11-10</periodOfReport>

    <dateOfOriginalSubmission>2023-11-16</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000740806</issuerCik>
        <issuerName>F&amp;M BANK CORP</issuerName>
        <issuerTradingSymbol>fmbm</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001375820</rptOwnerCik>
            <rptOwnerName>Willingham John A.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>925 MEADOW CT.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WINCHESTER</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22601</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2023-11-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The original Form 4, filed on November 16, 2023 (the &quot;Original Form 4&quot;), is being amended by this Form 4 amendment to reflect the deletion of the transaction reported in Table 1 on the Reporting Person's Original Form 4, which transaction incorrectly reported the disposition by the Reporting Person of 1,040 shares of the Issuer's common stock (the &quot;Shares&quot;) held indirectly by a 401k. The Reporting Person does not in fact hold any Shares indirectly or via a 401k. The transaction reflected on this amended Form 4 is not a new transaction but is included to allow access to the reporting system.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Candy F. Barkley, Attorney-in-Fact</signatureName>
        <signatureDate>2023-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
