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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-09-01</periodOfReport>

    <notSubjectToSection16>true</notSubjectToSection16>

    <issuer>
        <issuerCik>0000866829</issuerCik>
        <issuerName>HORNBECK OFFSHORE SERVICES, INC.</issuerName>
        <issuerTradingSymbol>HOS</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001946868</rptOwnerCik>
            <rptOwnerName>Glassman Diana</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>3505 WEST SAM HOUSTON PKWY NORTH</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 400</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <remarks>On August 31, 2026, the reporting person gave notice to Hornbeck Offshore Services, Inc. (formerly named Helix Energy Solutions Group, Inc.) (the &quot;Issuer&quot;) resigning from the board of directors of the Issuer. Such resignation was effective as of September 1, 2026. As a result, the reporting person is no longer subject to Section 16 in connection with her transactions in the equity securities of the Issuer and therefore will no longer report any such transactions on Form 4 or Form 5.</remarks>

    <ownerSignature>
        <signatureName>/s/ Diana Glassman</signatureName>
        <signatureDate>2026-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
