X0306 4 2022-10-28 0001049502 MKS INSTRUMENTS INC MKSI 0001192439 BAGSHAW SETH H C/O MKS INSTRUMENTS, INC. 2 TECH DRIVE, SUITE 201 ANDOVER MA 01810 1 Sr. VP, CFO & Treasurer Common Stock 2022-10-28 4 M 0 4358.058 A 36223.938 D Common Stock 2022-10-28 4 F 0 1933 84.58 D 34290.938 D Restricted Stock Unit 2022-10-28 4 M 0 4358.058 D Common Stock 4358.058 24440.016 D Each restricted stock unit (RSU) represents the contingent right to receive one share of common stock of MKS Instruments, Inc. This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person. These RSUs vest in two equal annual installments on each of the second anniversary and third anniversary of the date of grant, October 28, 2019. /s/ M. Kathryn Rickards, attorney-in-fact 2022-10-31