<SEC-DOCUMENT>0001221590-26-000021.txt : 20260617
<SEC-HEADER>0001221590-26-000021.hdr.sgml : 20260617
<ACCEPTANCE-DATETIME>20260617165550
ACCESSION NUMBER:		0001221590-26-000021
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260615
FILED AS OF DATE:		20260617
DATE AS OF CHANGE:		20260617

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BIENAIME JEAN JACQUES
		CENTRAL INDEX KEY:			0001221590
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39264
		FILM NUMBER:		261099282

	MAIL ADDRESS:	
		STREET 1:		925 PAGE MILL ROAD
		CITY:			PALO ALTO
		STATE:			CA
		ZIP:			94304

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>form4-06172026_080646.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-06-15</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001221590</rptOwnerCik>
            <rptOwnerName>BIENAIME JEAN JACQUES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <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>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.19</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17592</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares were purchased pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 5, 2025.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $9.99 to $10.34 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Esther Cho, Attorney-in-Fact</signatureName>
        <signatureDate>2026-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
