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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-07-03</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000808362</issuerCik>
        <issuerName>BAKER HUGHES a GE Co LLC</issuerName>
        <issuerTradingSymbol>BHI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001164027</rptOwnerCik>
            <rptOwnerName>BRENNEMAN GREGORY D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>17021 ALDINE WESTFIELD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77073</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $1.00 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>93711</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-07-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2751</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, $1.00 Par Value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2751</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On the closing date (the &quot;Closing Date&quot;) of the transactions contemplated by the Transaction Agreement and Plan of Merger, dated as of October 30, 2016, among General Electric Company, a New York corporation, Baker Hughes Incorporated, a Delaware corporation (&quot;BHI&quot;), the Issuer and certain subsidiaries of BHI, as amended by that certain Amendment to Transaction Agreement and Plan of Merger dated as of March 27, 2017 (the &quot;Transaction Agreement&quot;), each outstanding share of common stock of the Issuer (&quot;BHI Common Stock&quot;), whether restricted or unrestricted, was cancelled and converted into the right to receive (a) one share of Class A common stock of Baker Hughes, a GE Company (&quot;BHGE Common Stock&quot;) and (b) a special one-time cash dividend of $17.50 per share of BHGE Common Stock (the &quot;Special Dividend&quot;).</footnote>
        <footnote id="F2">Prior to the Closing Date, each restricted stock unit represented a contingent right to one share of BHI Common Stock (each, a &quot;BHI RSU&quot;). Pursuant to the Transaction Agreement, on the Closing Date, each outstanding BHI RSU was cancelled and converted into a restricted stock unit with respect to a share of BHGE Common Stock, with the same terms and conditions as applied to such BHI RSU immediately prior to the Closing Date (including the right with respect to the Special Dividend).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Lee Whitley, Attorney-in-Fact</signatureName>
        <signatureDate>2017-07-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
