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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2018-03-08</periodOfReport>

    <dateOfOriginalSubmission>2018-01-25</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000766421</issuerCik>
        <issuerName>ALASKA AIR GROUP, INC.</issuerName>
        <issuerTradingSymbol>ALK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001729220</rptOwnerCik>
            <rptOwnerName>BECK GARY L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19300 INTERNATIONAL BLVD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98188</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>PRES &amp; CEO/HORIZON AIR</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>EMPLOYEE STOCK OPTION (RT TO BUY)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2016-02-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1620</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>EMPLOYEE STOCK OPTION (RT TO BUY)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>24.4</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2017-02-11</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2860</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>EMPLOYEE STOCK OPTION (RT TO BUY)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>38.755</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2018-02-11</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3400</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>EMPLOYEE STOCK OPTION (RT TO BUY)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>65.37</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2018-02-10</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1520</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">STOCK OPTIONS PREVIOUSLY GRANTED TO MR. BECK ON 2/14/12, 2/11/13, 2/11/14, AND 2/10/15 WERE INADVERTENTLY OMITTED FROM THE FORM 3 ORIGINALLY FILED ON 1/25/18.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>JEANNE E GAMMON, ATTORNEY IN FACT FOR GARY L BECK</signatureName>
        <signatureDate>2018-03-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
