<SEC-DOCUMENT>0001049502-25-000037.txt : 20251104
<SEC-HEADER>0001049502-25-000037.hdr.sgml : 20251104
<ACCEPTANCE-DATETIME>20251104170143
ACCESSION NUMBER:		0001049502-25-000037
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251031
FILED AS OF DATE:		20251104
DATE AS OF CHANGE:		20251104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Burke Kathleen Flaherty
		CENTRAL INDEX KEY:			0001775435
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23621
		FILM NUMBER:		251450465

	MAIL ADDRESS:	
		STREET 1:		MKS INSTRUMENTS, INC., 2 TECH DRIVE
		STREET 2:		SUITE 201
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MKS INC
		CENTRAL INDEX KEY:			0001049502
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				042277512
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2 TECH DRIVE
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810
		BUSINESS PHONE:		978-645-5500

	MAIL ADDRESS:	
		STREET 1:		2 TECH DRIVE
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MKS INSTRUMENTS INC
		DATE OF NAME CHANGE:	19971112
</SEC-HEADER>
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    <footnotes>
        <footnote id="F1">Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.</footnote>
        <footnote id="F2">Shares used to satisfy FICA taxes.</footnote>
        <footnote id="F3">Portion of 2023 RSU Award accelerated to satisfy FICA taxes.</footnote>
        <footnote id="F4">Portion of 2024 RSU Award accelerated to satisfy FICA taxes.</footnote>
        <footnote id="F5">Portion of 2025 RSU Award accelerated to satisfy FICA taxes.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ M. Kathryn Rickards, attorney-in-fact</signatureName>
        <signatureDate>2025-11-04</signatureDate>
    </ownerSignature>
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</SEC-DOCUMENT>
