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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-09-10</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001059142</issuerCik>
        <issuerName>AMERICA FIRST MULTIFAMILY INVESTORS, L.P.</issuerName>
        <issuerTradingSymbol>ATAX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185544</rptOwnerCik>
            <rptOwnerName>KRAUSS GEORGE H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1004 FARNAM STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OMAHA</rptOwnerCity>
            <rptOwnerState>NE</rptOwnerState>
            <rptOwnerZipCode>68102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <remarks>Effective September 10, 2019, as a result of Burlington Capital LLC's sale of its interests in America First Capital Associates Limited Partnership Two, the general partner of the Issuer, to affiliates of Greystone &amp; Co, Inc., Mr. Krauss, as a member of the Board of Managers of Burlington Capital LLC, resigned his role with respect to the Issuer, including in his capacity as the equivalent of a director of the Issuer. As a result, Mr. Krauss is no longer subject to Section 16 in connection with his transactions in the equity securities of the Issuer.</remarks>

    <ownerSignature>
        <signatureName>/s/ George H. Krauss</signatureName>
        <signatureDate>2019-09-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
