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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-05-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001602367</issuerCik>
        <issuerName>Adeptus Health Inc.</issuerName>
        <issuerTradingSymbol>ADPT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001611617</rptOwnerCik>
            <rptOwnerName>5-N Investments, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DEUTSCHE BANK SECURITIES INC.</rptOwnerStreet1>
            <rptOwnerStreet2>200 CRESCENT COURT, SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001611618</rptOwnerCik>
            <rptOwnerName>Novak Jacob John</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DEUTSCHE BANK SECURITIES INC.</rptOwnerStreet1>
            <rptOwnerStreet2>200 CRESCENT COURT, SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Units of Adeptus Health LLC</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-05-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>60.08</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1647778</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Units of Adeptus Health LLC represent limited liability company units of Adeptus Health LLC and an equal number of shares of Class B Common Stock of the Issuer, which together are exchangeable on a one-for-one basis for shares of Class A Common Stock of the Issuer pursuant to the Amended and Restated Limited Liability Company Agreement of Adeptus Health LLC.</footnote>
        <footnote id="F2">Represents a purchase of limited liability company units of Adeptus Health LLC by the Issuer from 5-N Investments, LLC at $63.75 per share, the public offering price per share of Class A Common Stock, less an amount equal to the underwriting discount of $3.665624 per share. In connection with the purchase, an equivalent number of shares of Class B Common Stock of the Issuer were cancelled.</footnote>
        <footnote id="F3">Units of Adeptus Health LLC are held by 5-N Investments LLC, which is managed by Dr. Jacob John Novak. Dr. Novak disclaims beneficial ownership of the securities reported herein, except to the extent of his pecuniary interest therein. The filing of this statement shall not be deemed to be an admission that, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, Dr. Novak is the beneficial owner of any securities reported herein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jacob John Novak, manager of 5-N Investments, LLC</signatureName>
        <signatureDate>2015-05-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jacob John Novak</signatureName>
        <signatureDate>2015-05-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
