<SEC-DOCUMENT>0001950047-24-000626.txt : 20240202
<SEC-HEADER>0001950047-24-000626.hdr.sgml : 20240202
<ACCEPTANCE-DATETIME>20240202163550
ACCESSION NUMBER:		0001950047-24-000626
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20240202
DATE AS OF CHANGE:		20240202

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Merck & Co., Inc.
		CENTRAL INDEX KEY:			0000310158
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				221918501
		STATE OF INCORPORATION:			NJ
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	001-06571
		FILM NUMBER:		24592113

	BUSINESS ADDRESS:	
		STREET 1:		2000 GALLOPING HILL ROAD
		CITY:			KENILWORTH
		STATE:			NJ
		ZIP:			07033
		BUSINESS PHONE:		908-740-4000

	MAIL ADDRESS:	
		STREET 1:		2000 GALLOPING HILL ROAD
		CITY:			KENILWORTH
		STATE:			NJ
		ZIP:			07033

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Merck & Co. Inc.
		DATE OF NAME CHANGE:	20091103

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SCHERING PLOUGH CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Oosthuizen Johannes Jacobus
		CENTRAL INDEX KEY:			0001916310
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		2000 GALLOPING HILL RD
		CITY:			KENILWORTH
		STATE:			NJ
		ZIP:			07033
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
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    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001916310</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0000310158</issuerCik>
            <issuerName>MERCK &amp; CO. INC.</issuerName>
            <secFileNumber>001-06571</secFileNumber>
            <issuerAddress>
                <ns2:street1>126 East Lincoln Avenue</ns2:street1>
                <ns2:city>Rahway</ns2:city>
                <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                <ns2:zipCode>07065</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>908-740-4000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>JOHANNES JACOBUS OOSTHUIZEN</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>18959</noOfUnitsSold>
            <aggregateMarketValue>2411110.83</aggregateMarketValue>
            <noOfUnitsOutstanding>2534023084</noOfUnitsOutstanding>
            <approxSaleDate>02/02/2024</approxSaleDate>
            <securitiesExchangeName>NYSE</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/02/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of options under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>6006</amountOfSecuritiesAcquired>
            <paymentDate>02/02/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>01/23/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1938</amountOfSecuritiesAcquired>
            <paymentDate>01/23/2023</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/02/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of options under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>5451</amountOfSecuritiesAcquired>
            <paymentDate>02/02/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/02/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of options under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>5564</amountOfSecuritiesAcquired>
            <paymentDate>02/02/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>JOHANNES JACOBUS OOSTHUIZEN</name>
                <address>
                    <ns2:street1>126 East Lincoln Avenue</ns2:street1>
                    <ns2:city>Rahway</ns2:city>
                    <ns2:stateOrCountry>NJ</ns2:stateOrCountry>
                    <ns2:zipCode>07065</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>11/09/2023</saleDate>
            <amountOfSecuritiesSold>2081</amountOfSecuritiesSold>
            <grossProceeds>213061.31</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>02/02/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Johannes J Oosthuizen</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
