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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-05-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001756262</issuerCik>
        <issuerName>TransMedics Group, Inc.</issuerName>
        <issuerTradingSymbol>TMDX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001255927</rptOwnerCik>
            <rptOwnerName>KANIA EDWIN M JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TRANSMEDICS GROUP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>200 MINUTEMAN ROAD</rptOwnerStreet2>
            <rptOwnerCity>ANDOVER</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01810</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

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L.P.</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By OneLiberty Advisors Fund 2000, L.P.</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Series C Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-05-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>31383</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</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8966</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By OneLiberty Advisors Fund 2000, L.P.</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Series D Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-05-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</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</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5714</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By OneLiberty Advisors Fund 2000, L.P.</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Series D Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-05-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>200000</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</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>57142</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>OneLiberty
Ventures, Inc.</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Common Stock reported herein as being disposed of is common stock of TransMedics, Inc. Immediately prior to the closing of the Issuer's initial public offering, pursuant to the terms of Agreement and Plan of Merger and Reorganization by and among the Issuer, TransMedics, Inc. and TMDX, Inc., dated April 15, 2019 (the &quot;Merger Agreement&quot;), such common stock of TransMedics, Inc. was converted into shares of common stock of the Issuer on a 3.5-for-one basis.</footnote>
        <footnote id="F2">The Preferred Stock reported herein is preferred stock of TransMedics, Inc. Immediately prior to the closing of the Issuer's initial public offering, pursuant to the Merger Agreement, such Series C, D and F preferred stock of TransMedics, Inc. was converted into shares of common stock of the Issuer based on (i) the one-for-one ratio on which such shares of preferred stock of TransMedics Inc. were convertible into shares of common stock of TransMedics Inc. according to their terms and (ii) the 3.5-for-one ratio on which shares of common stock of TransMedics, Inc. were converted into shares of common stock of the Issuer. The Preferred Stock has no expiration date.</footnote>
        <footnote id="F3">The Preferred Stock reported herein is preferred stock of TransMedics, Inc. Immediately prior to the closing of the Issuer's initial public offering, pursuant to the Merger Agreement, each outstanding share of Series A-1 preferred stock of TransMedics, Inc. was converted into shares of common stock of the Issuer based on (i) the ratio on which such shares of preferred stock of TransMedics Inc. were convertible into shares of common stock of TransMedics Inc. according to their terms, determined by dividing the original issue price of $2.50 per share by a conversion price of $9.680, and (ii) the 3.5-for-one ratio on which shares of common stock of TransMedics, Inc. were converted into shares of common stock of the Issuer. The Preferred Stock has no expiration date.</footnote>
        <footnote id="F4">The Preferred Stock reported herein is preferred stock of TransMedics, Inc. Immediately prior to the closing of the Issuer's initial public offering, pursuant to the Merger Agreement, each outstanding share of Series B-1 preferred stock of TransMedics, Inc. was converted into shares of common stock of the Issuer based on (i) the ratio on which such shares of preferred stock of TransMedics Inc. were convertible into shares of common stock of TransMedics Inc. according to their terms, determined by dividing the original issue price of $3.416 per share by a conversion price of $12.365, and (ii) the 3.5-for-one ratio on which shares of common stock of TransMedics, Inc. were converted into shares of common stock of the Issuer. The Preferred Stock has no expiration date.</footnote>
        <footnote id="F5">Edwin M. Kania, Jr. is a manager of OneLiberty Partners 2000, LLC, which is the general partner of OneLiberty Ventures 2000, L.P. (&quot;OneLiberty 2000&quot;) and OneLiberty Advisors Fund 2000, L.P. (&quot;OneLiberty Advisors 2000&quot; and together with OneLiberty 2000, the &quot;OneLiberty Funds&quot;). Mr. Kania is also the principal of OneLiberty Ventures, Inc., which is the management company for, and provides services in connection with the investment activities of, the OneLiberty Funds. By virtue of the foregoing relationships, Mr. Kania may be deemed to indirectly beneficially own the securities held by the OneLiberty Funds and OneLiberty Ventures, Inc., however he disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By: /s/ Stephen Gordon, Attorney-in-fact</signatureName>
        <signatureDate>2019-05-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
