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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-10-28</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001500096</issuerCik>
        <issuerName>Kayne Anderson NextGen Energy &amp; Infrastructure, Inc.</issuerName>
        <issuerTradingSymbol>KMF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000005272</rptOwnerCik>
            <rptOwnerName>AMERICAN INTERNATIONAL GROUP INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>175 WATER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10038</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000005181</rptOwnerCik>
            <rptOwnerName>AMERICAN HOME ASSURANCE CO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>175 WATER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10038</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000005108</rptOwnerCik>
            <rptOwnerName>AMERICAN GENERAL LIFE INSURANCE CO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2727-A ALLEN PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series C Mandatory Redeemable Preferred Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2020-10-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>498301</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.22</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The Series C Mandatory Redeemable Preferred Shares (the &quot;Series C MRPS&quot;) were redeemed by the issuer at a price equal to the principal amount of $25.00 of the redeemed securities, plus accrued interest of $0.22 per share.</footnote>
        <footnote id="F2">American Home Assurance Company and American General Life Insurance Company, each an indirect wholly owned subsidiary of American International Group, Inc. (&quot;AIG&quot;), directly held 166,931 shares and 331,370 shares, respectively, of the Series C MRPS. AIG is an indirect beneficial owner of the Series C MRPS.</footnote>
    </footnotes>

    <remarks>Filed pursuant to Section 30(h) of the Investment Company Act of 1940.</remarks>

    <ownerSignature>
        <signatureName>/s/ Geoffrey N. Cornell, Authorized Signatory of American International Group, Inc.</signatureName>
        <signatureDate>2020-10-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Martin J. Bogue, Authorized Signatory of American Home Assurance Company</signatureName>
        <signatureDate>2020-10-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Julie A. Cotton Hearne, Authorized Signatory of American General Life Insurance Company</signatureName>
        <signatureDate>2020-10-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
