<SEC-DOCUMENT>0001292814-26-001286.txt : 20260318
<SEC-HEADER>0001292814-26-001286.hdr.sgml : 20260318
<ACCEPTANCE-DATETIME>20260318212918
ACCESSION NUMBER:		0001292814-26-001286
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260317
FILED AS OF DATE:		20260318
DATE AS OF CHANGE:		20260318

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Metz Mauricio
		CENTRAL INDEX KEY:			0002120044
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14878
		FILM NUMBER:		26772038

	MAIL ADDRESS:	
		ADDRESS IS A NON US LOCATION: 	YES
		STREET 1:		AVENUE DOUTORA RUTH DE CARDOSO, 8501
		STREET 2:		8TH FLOOR, PINHEIROS
		CITY:			SAO PAULO
		NON US STATE TERRITORY:  	SAO PAULO
		PROVINCE COUNTRY:   	D5
		ZIP:			05425-070

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GERDAU S.A.
		CENTRAL INDEX KEY:			0001073404
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES & ROLLING & FINISHING MILLS [3310]
		ORGANIZATION NAME:           	04 Manufacturing
		EIN:				000000000
		STATE OF INCORPORATION:			D5
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		ADDRESS IS A NON US LOCATION: 	YES
		STREET 1:		AV DOUTORA RUTH CARDOSO, 8,501
		STREET 2:		8TH FLOOR
		CITY:			SAO PAULO, SP
		PROVINCE COUNTRY:   	D5
		ZIP:			05425-070
		BUSINESS PHONE:		011-55-51-3323-2703

	MAIL ADDRESS:	
		ADDRESS IS A NON US LOCATION: 	YES
		STREET 1:		AV DOUTORA RUTH CARDOSO, 8,501
		STREET 2:		8TH FLOOR
		CITY:			SAO PAULO, SP
		PROVINCE COUNTRY:   	D5
		ZIP:			05425-070

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GERDAU SA
		DATE OF NAME CHANGE:	19981112
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-03-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001073404</issuerCik>
        <issuerName>GERDAU S.A.</issuerName>
        <issuerTradingSymbol>GBB</issuerTradingSymbol>
        <issuerForeignTradingSymbol>GGBR</issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002120044</rptOwnerCik>
            <rptOwnerName>Metz Mauricio</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>true</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>AVENUE DOUTORA RUTH DE CARDOSO, 8501</rptOwnerStreet1>
            <rptOwnerStreet2>8TH FLOOR, PINHEIROS</rptOwnerStreet2>
            <rptOwnerCity>SAO PAULO</rptOwnerCity>
            <rptOwnerNonUSStateTerritory>SAO PAULO</rptOwnerNonUSStateTerritory>
            <rptOwnerCountry>D5</rptOwnerCountry>
            <rptOwnerZipCode>05425-070</rptOwnerZipCode>
            <rptOwnerStateDescription>BRAZIL</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Executive Vice President</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Preferred shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>43536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.50</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-02-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Preferred shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4060</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.50</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-02-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Preferred shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>32280</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.32</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-02-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Preferred shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6332</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>20.83</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2029-02-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Preferred shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6683</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted stock units vest on February 12, 2027. Exercise price denominated in Brazilian reais (R$).</footnote>
        <footnote id="F2">Restricted stock units vest on February 22, 2027. Exercise price denominated in Brazilian reais (R$).</footnote>
        <footnote id="F3">Restricted stock units vest on February 12, 2028. Exercise price denominated in Brazilian reais (R$).</footnote>
        <footnote id="F4">Restricted stock units vest on February 12, 2029. Exercise price denominated in Brazilian reais (R$).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Mauricio Metz</signatureName>
        <signatureDate>2026-03-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
