MKS INC — Director's Dealing 2026

Feb 9, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INC (MKSI)
CIK: 0001049502
Period of Report: 2026-02-08

Reporting Person: Mayampurath Ramakumar (EVP & CFO)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-08	Restricted Stock Unit	$	A	8877.596	Acquired		Common Stock (8877.596)	Direct

Footnotes

F1: Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Inc.

F2: These RSUs were subject to performance criteria, the achievement of which was determined on February 8, 2026, and thereafter vest in three equal annual installments beginning 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.