James Alan Schreiner - 04 Aug 2025 Form 4 Insider Report for MKS INC (MKSI)

Role: EVP & COO
Signature: /s/ M. Kathryn Rickards, attorney-in-fact
Issuer symbol: MKSI
Transactions as of: 04 Aug 2025
Net transactions value: $0
Form type: 4
Filing time: 05 Aug 2025, 11:54:55 UTC
Previous filing: 08 Jul 2025
Next filing: 19 Aug 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Schreiner James Alan	EVP & COO	C/O MKS INC., 2 TECH DRIVE, ANDOVER	/s/ M. Kathryn Rickards, attorney-in-fact	05 Aug 2025	0001797189

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MKSI	Restricted Stock Unit	Award		+1,330	+9.3%		15,659	04 Aug 2025	Common Stock	1,330		Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.
F2	These RSUs vest in three equal annual installments commencing on February 15, 2026, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.