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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2019-07-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001412408</issuerCik>
        <issuerName>Phreesia, Inc.</issuerName>
        <issuerTradingSymbol>PHR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439589</rptOwnerCik>
            <rptOwnerName>Polaris Venture Management Co. V, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439588</rptOwnerCik>
            <rptOwnerName>Polaris Venture Partners Founders' Fund V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439590</rptOwnerCik>
            <rptOwnerName>Polaris Venture Partners V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439587</rptOwnerCik>
            <rptOwnerName>Polaris Venture Partners Entrepreneurs' Fund V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001439586</rptOwnerCik>
            <rptOwnerName>Polaris Venture Partners Special Founders' Fund V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001295676</rptOwnerCik>
            <rptOwnerName>Flint Jonathan A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001117003</rptOwnerCik>
            <rptOwnerName>MCGUIRE TERRANCE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POLARIS PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE MARINA PARK DRIVE, 10TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Junior Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3828872</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Polaris Venture Partners V, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Junior Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>74624</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Polaris Venture Partners Entrepreneurs' Fund V, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Junior Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>26227</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Polaris Venture Partners Founders' Fund V, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Junior Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>38289</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Polaris Venture Partners Special Founders' Fund V, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Junior Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a one-for-2.1973 basis. Upon the closing of the Issuer's initial public offering, all shares of Junior Convertible Preferred Stock will automatically convert into shares of Common Stock of the Issuer. The Junior Convertible Preferred Stock has no expiration date.</footnote>
        <footnote id="F2">Jonathan A. Flint (&quot;Flint&quot;) and Terrance G. McGuire (&quot;McGuire&quot;) are the managing members of Polaris Venture Management Co. V, L.L.C. (&quot;PVM&quot;), which is the sole general partner for each of Polaris Venture Partners V, L.P. (&quot;PVP V&quot;), Polaris Venture Partners Entrepreneurs' Fund V, L.P. (&quot;PVPEF V&quot;), Polaris Venture Partners Founders' Fund V, L.P. (&quot;PVPFF V&quot;), and Polaris Venture Partners Special Founders' Fund V, L.P. (&quot;PVPSF V&quot;, and together with PVP V, PVPEF V, and PVPFF V, the &quot;Polaris Funds&quot;). Each of Flint, McGuire, and PVM may be deemed to beneficially own the shares held by the Polaris Funds, but Flint, McGuire, and PVM disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests therein.</footnote>
    </footnotes>

    <remarks>Exhibit 24 - Power of Attorney for Jonathan A. Flint and Terrance G. McGuire</remarks>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Polaris Venture Management Co. V, L.L.C.</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Polaris Venture Partners V, L.P.</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Polaris Venture Partners Entrepreneurs' Fund V, L.P.</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Polaris Venture Partners Founders' Fund V, L.P.</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Polaris Venture Partners Special Founders' Fund V, L.P.</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Jonathan A. Flint</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Lauren Crockett, as attorney-in-fact for Terrance G. McGuire</signatureName>
        <signatureDate>2019-07-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
