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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-02-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001723128</issuerCik>
        <issuerName>Amneal Pharmaceuticals, Inc.</issuerName>
        <issuerTradingSymbol>AMRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001738701</rptOwnerCik>
            <rptOwnerName>Patel Chirag K.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AMNEAL PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>400 CROSSING BOULEVARD, 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BRIDGEWATER</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08807</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, Co-CEO &amp; Director</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance-Based Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-02-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1266490</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1266490</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1266490</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each performance-based restricted stock unit represents a contingent right to receive one share of the Issuer's Class A Common Stock.</footnote>
        <footnote id="F2">Represents the maximum number of shares issuable under the performance-based restricted stock units.</footnote>
        <footnote id="F3">25% of the performance-based restricted stock units are earned and eligible to vest upon the Issuer's Class A Common Stock achieving an average closing price per share of $8 or higher for 60 consecutive calendar days during the three-year performance period. An additional 12.5% of the performance-based restricted stock units are earned and eligible to vest upon the Issuer's Class A Common Stock achieving an average closing price per share of $10, $12, $14, $16, $18 and $20, respectively, for 60 consecutive calendar days during the three-year performance period. For average 60-day closing stock prices between $12 and $20 per share, the number of performance-based restricted stock units that become earned will be determined using straight line interpolation. Any earned performance-based restricted stock units vest in full on February 28, 2023, the last day of the performance period.</footnote>
    </footnotes>

    <remarks>Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Meredith Cook, Attorney-in-Fact</signatureName>
        <signatureDate>2020-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
