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

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-03-31</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0002021880</issuerCik>
        <issuerName>HMH Holding Inc</issuerName>
        <issuerTradingSymbol>HMH</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002037057</rptOwnerCik>
            <rptOwnerName>Akastor ASA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>OKSENOYVEIEN 10</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LYSAKER</rptOwnerCity>
            <rptOwnerNonUSStateTerritory></rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>Q8</rptOwnerCountry>
            <rptOwnerZipCode>1366</rptOwnerZipCode>
            <rptOwnerStateDescription>NORWAY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002124921</rptOwnerCik>
            <rptOwnerName>Akastor AS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>OKSENOYVEIEN 10</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LYSAKER</rptOwnerCity>
            <rptOwnerNonUSStateTerritory></rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>Q8</rptOwnerCountry>
            <rptOwnerZipCode>1366</rptOwnerZipCode>
            <rptOwnerStateDescription>NORWAY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>true</isOther>
            <otherText>Director by Deputization</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002124920</rptOwnerCik>
            <rptOwnerName>Mercury HoldCo AS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>OKSENOYVEIEN 10</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LYSAKER</rptOwnerCity>
            <rptOwnerNonUSStateTerritory></rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>Q8</rptOwnerCountry>
            <rptOwnerZipCode>1366</rptOwnerZipCode>
            <rptOwnerStateDescription>NORWAY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002124922</rptOwnerCik>
            <rptOwnerName>Mercury HoldCo Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>3300 NORTH SAM HOUSTON PARKWAY EAST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77032</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>true</isOther>
            <otherText>Director by Deputization</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>B.V. Voting Class A Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>B.V. Voting Class B Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Prior to the initial public offering (&quot;IPO&quot;) of HMH Holding Inc. (the &quot;Issuer&quot;), (a) Akastor AS, a direct wholly owned subsidiary of Akastor ASA, holds 50 Class B ordinary shares (the &quot;B.V. Voting Class B Shares&quot;) of HMH Holding B.V. (&quot;HMH B.V.&quot;) and (b) Mercury HoldCo Inc., an indirect wholly owned subsidiary of Akastor ASA (with Mercury HoldCo AS as an intermediary subsidiary between Akastor ASA and Mercury HoldCo Inc.) holds 50 Class A ordinary shares (the &quot;B.V. Voting Class A Shares&quot;) of HMH B.V. In this filing, Akastor ASA, Akastor AS, Mercury HoldCo AS and Mercury HoldCo Inc. are collectively referred to as &quot;Akastor&quot;. (cont'd in fn 2)</footnote>
        <footnote id="F2">(cont'd from fn 1) In connection with the corporate reorganization and Akastor's participation in the synthetic secondary as described in the Issuer's Registration Statement on Form S-1 (Registration No. 333-281497), it is anticipated that the following transactions will occur: first, HMH B.V., the predecessor entity to the Issuer that will become a subsidiary of the Issuer in connection with the aforementioned corporate reorganization and the Issuer's IPO, will undergo a stock split, after which Akastor will hold additional B.V. Voting Class B Shares (through Akastor AS) and additional B.V. Voting Class A Shares (through Mercury HoldCo Inc.); second, HMH B.V. will recapitalize to convert (i) a portion of its B.V. Voting Class A Shares to non-voting Class A ordinary shares (the &quot;B.V. Non-Voting Class A Shares&quot;) and (ii) a portion of its B.V. Voting Class B Shares to non-voting Class B ordinary shares (the &quot;B.V. Non-Voting Class B Shares&quot;); (cont'd in fn 3)</footnote>
        <footnote id="F3">(cont'd from fn 2) third, (i) Akastor AS will sell the remaining B.V. Voting Class B Shares held by it, and Mercury HoldCo Inc. will sell the remaining B.V. Voting Class A Shares held by it, in each case, to the Issuer in exchange for cash and (ii) each of Akastor AS and Mercury HoldCo Inc. will receive shares of Class B common stock of the Issuer (the &quot;Issuer Class B Shares&quot;) in exchange for relinquishing voting rights on their respective remaining B.V. Voting Class B Shares and B.V. Voting Class A Shares that were recapitalized into B.V. Non-Voting Class B Shares and B.V. Non-Voting Class A Shares, respectively.</footnote>
        <footnote id="F4">Akastor ASA has an indirect pecuniary interest in the securities held by each of Akastor AS and Mercury HoldCo Inc. Mercury HoldCo AS has an indirect pecuniary interest in the securities held by Mercury HoldCo Inc. Consequently, Akastor ASA may be deemed to share beneficial ownership in the securities held directly by Akastor AS, and Akastor ASA and Mercury HoldCo AS may be deemed to share beneficial ownership in the securities held directly by Mercury HoldCo Inc. The board of directors and officers of Akastor ASA, Mercury HoldCo Inc., Akastor AS and Mercury HoldCo AS disclaim beneficial ownership with respect to such securities.</footnote>
        <footnote id="F5">Pursuant to the Exchange Agreement, to be dated on or about April 2, 2026, by and among the Issuer, HMH B.V. and the other parties thereto, Akastor will have the right to exchange one Issuer Class B Share, one B.V. Non-Voting Class A Share and one B.V. Non-Voting Class B Share for cash or shares of the Issuer's Class A common stock on a one-for-one basis, subject to customary conversion rate adjustments (e.g. for stock splits, stock dividends and reclassifications). These rights are exercisable at any time after the conclusion of the Issuer's IPO lock-up period (i.e., September 27, 2026, unless the IPO lock-up is earlier released or waived by the underwriters of the Issuer's IPO) and do not expire.</footnote>
        <footnote id="F6">Karl Erik Kjelstad and Svein Oskar Stoknes are directors of the Issuer and were nominated for such roles by Akastor AS and Mercury HoldCo Inc. By virtue of their service on the Board of Directors of the Issuer, for purposes of Section 16, Akastor AS and Mercury HoldCo Inc. may be deemed to be a &quot;director by deputization&quot; of the Issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Karl Erik Kjelstad, as Chief Executive Officer of Akastor ASA</signatureName>
        <signatureDate>2026-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Oyvind Paaske, Chair of Akastor AS</signatureName>
        <signatureDate>2026-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Oyvind Paaske, Chair of Mercury HoldCo AS</signatureName>
        <signatureDate>2026-03-31</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Askel Matre, Director of Mercury HoldCo Inc.</signatureName>
        <signatureDate>2026-03-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
