<SEC-DOCUMENT>0002081359-26-000005.txt : 20260226
<SEC-HEADER>0002081359-26-000005.hdr.sgml : 20260226
<ACCEPTANCE-DATETIME>20260226161517
ACCESSION NUMBER:		0002081359-26-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260224
FILED AS OF DATE:		20260226
DATE AS OF CHANGE:		20260226

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lerner Lorena Raquel
		CENTRAL INDEX KEY:			0002081359
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39264
		FILM NUMBER:		26688266

	MAIL ADDRESS:	
		STREET 1:		C/O KEROS THERAPEUTICS, INC.
		STREET 2:		1050 WALTHAM STREET, SUITE 302
		CITY:			LEXINGTON
		STATE:			MA
		ZIP:			02421

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Keros Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001664710
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				811173868
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1050 WALTHAM STREET, SUITE 302
		CITY:			LEXINGTON
		STATE:			MA
		ZIP:			02421
		BUSINESS PHONE:		617-314-6297

	MAIL ADDRESS:	
		STREET 1:		1050 WALTHAM STREET, SUITE 302
		CITY:			LEXINGTON
		STATE:			MA
		ZIP:			02421
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4-02262026_040210.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-02-24</periodOfReport>

    <issuer>
        <issuerCik>0001664710</issuerCik>
        <issuerName>Keros Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>KROS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002081359</rptOwnerCik>
            <rptOwnerName>Lerner Lorena Raquel</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O KEROS THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1050 WALTHAM STREET, SUITE 302</rptOwnerStreet2>
            <rptOwnerCity>LEXINGTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02421</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Chief Scientific Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-02-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>75000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2036-02-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>75000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">One-fourth (1/4th) of the shares subject to the option shall vest on February 24, 2027, and the remaining shares subject to the option shall vest in twelve substantially equal quarterly installments thereafter, subject to the Reporting Person continuing to provide service through each such date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Esther Cho, Attorney-in-Fact</signatureName>
        <signatureDate>2026-02-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
