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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-18</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001377630</issuerCik>
        <issuerName>National CineMedia, Inc.</issuerName>
        <issuerTradingSymbol>NCMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001411579</rptOwnerCik>
            <rptOwnerName>AMC ENTERTAINMENT HOLDINGS, INC.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE AMC WAY</rptOwnerStreet1>
            <rptOwnerStreet2>11500 ASH STREET</rptOwnerStreet2>
            <rptOwnerCity>LEAWOOD</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000780392</rptOwnerCik>
            <rptOwnerName>AMERICAN MULTI-CINEMA, INC.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE AMC WAY</rptOwnerStreet1>
            <rptOwnerStreet2>11500 ASH STREET</rptOwnerStreet2>
            <rptOwnerCity>LEAWOOD</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001661466</rptOwnerCik>
            <rptOwnerName>AMC STARPLEX, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE AMC WAY</rptOwnerStreet1>
            <rptOwnerStreet2>11500 ASH STREET</rptOwnerStreet2>
            <rptOwnerCity>LEAWOOD</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66211</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Units of National Cinemedia, LLC</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-06-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>21477480</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>National Cinemedia, Inc. Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>21477480</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Common Units of National Cinemedia, LLC (&quot;NCM LLC&quot;) may be converted at any time into shares of the Issuer on a one-for-one basis and have no expiration date.</footnote>
        <footnote id="F2">Of the securities sold, 8,309,597 Common Units were held directly by AMC Starplex, LLC (&quot;AMCS&quot;) and 13,167,883 Common Units were held directly by American Multi-Cinema, Inc (&quot;AMCI&quot;).  AMCI also indirectly held 8,309,597 Common Units through AMCS, a wholly-owned subsidiary.  AMC Entertainment Holdings, Inc, that parent of AMCI, indirectly held all securities sold.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Edwin F. Gladbach, Vice President Legal &amp; Asst Secretary, AMC Entertainment Holdings, Inc.</signatureName>
        <signatureDate>2018-06-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Edwin F. Gladbach, Vice President Legal &amp; Asst Secretary, American Multi-Cinema, Inc.</signatureName>
        <signatureDate>2018-06-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Edwin F. Gladbach, Vice President Legal &amp; Asst Secretary, AMC Starplex, LLC</signatureName>
        <signatureDate>2018-06-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
