MKSI

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 6

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,951.606

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 5

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,694.606

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 4

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,432.606

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 3

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,482.606

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 2

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,493.606

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006520 · form4.xml · nonDerivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 15,031.082

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006533 · form4.xml · derivative · entry 1

Schreiner James Alan · CIK 0001797189 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,386.787

Underlying: Common Stock · 2,085.712 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 14

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,051.824

Underlying: Common Stock · 1,574.183 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F9 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F9 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 13

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,626.007

Underlying: Common Stock · 1,290.83 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F8 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F8 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 12

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,916.837

Underlying: Common Stock · 1,050 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F7 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F7 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 11

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,966.837

Underlying: Common Stock · 1,071 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F6 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F6 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 10

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,037.837

Underlying: Common Stock · 1,293.4 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 9

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,331.237

Underlying: Common Stock · 1,564.654 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · derivative · entry 8

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,895.891

Underlying: Common Stock · 3,842.101 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 7

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 34,307.069

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 6

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,774.069

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 5

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,199.886

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 4

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,909.056

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 3

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 32,859.056

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 2

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,788.056

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006529 · form4.xml · nonDerivative · entry 1

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 30,494.656

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 14

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,022.461

Underlying: Common Stock · 2,642.821 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F9 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F9 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 13

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,665.282

Underlying: Common Stock · 3,065.722 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F8 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F8 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 12

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 36,731.004

Underlying: Common Stock · 1,871 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F7 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F7 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 11

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 38,602.004

Underlying: Common Stock · 2,202 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F6 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F6 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2019, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 10

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,804.004

Underlying: Common Stock · 2,834.629 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F5 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 9

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 43,638.633

Underlying: Common Stock · 3,429.781 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F4 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant and thereafter vest in three equal annual installments beginning on February 15, 2018, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · derivative · entry 8

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,068.414

Underlying: Common Stock · 6,816.984 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F3 · derivative.expiration_date: These RSUs vest in three equal annual installments commencing on February 15, 2021, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 7

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 29,051.085

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 6

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,055.085

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 5

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 32,412.264

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 4

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 29,346.542

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 3

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,475.542

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 2

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,273.542

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006523 · form4.xml · nonDerivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,438.913

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-006516 · form4.xml · derivative · entry 5

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 76,125.261

Underlying: Common Stock · 7,260.921 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant. These RSUs vest on February 18, 2020.

F3 · derivative.expiration_date: These RSUs are subject to the achievement of performance criteria determined in the first year of grant. These RSUs vest on February 18, 2020.

SEC source: 0001127602-20-006516 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,039.921

F2 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-20-006516 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,260.921

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

SEC source: 0001127602-20-003734 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By The Gerald G. Colella Living Trust

Disclosed balance after: 50,748

F1 · price: This transaction was executed in multiple trades at prices ranging from $112.58 to $113.47. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, the full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0001127602-20-002535 · form4.xml · derivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Director · President & CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,821.963

Underlying: Common Stock · 9,197.167 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-002539 · form4.xml · derivative · entry 1

Burke Kathleen Flaherty · CIK 0001775435 · Sr. VP, GC & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,053.79

Underlying: Common Stock · 3,872.491 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-002537 · form4.xml · derivative · entry 1

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 40,251.43

Underlying: Common Stock · 9,197.167 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020 and thereafter vest in three equal annual installments beginning on February 15, 2020, provided that if, in any vesting year, February 15th is not a business day, such vesting shall occur on the next business day.

SEC source: 0001127602-20-002533 · form4.xml · derivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 83,386.182

Underlying: Common Stock · 21,782.763 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F2 · derivative.exercise_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020. On January 1, 2020, Mr. Colella retired as Chief Executive Officer of the Company. Pursuant to the terms of his restricted stock unit agreement governing this award, upon retirement, all of these RSUs will vest on February 18, 2020 but only 7,260.921 shares will be distributed on this date. The remaining shares are subject to Section 409A of the Internal Revenue Code and will be distributed on July 2, 2020.

F2 · derivative.expiration_date: These RSUs were subject to performance criteria, achievement of which was determined on January 27, 2020. On January 1, 2020, Mr. Colella retired as Chief Executive Officer of the Company. Pursuant to the terms of his restricted stock unit agreement governing this award, upon retirement, all of these RSUs will vest on February 18, 2020 but only 7,260.921 shares will be distributed on this date. The remaining shares are subject to Section 409A of the Internal Revenue Code and will be distributed on July 2, 2020.

SEC source: 0001127602-19-034665 · form4.xml · derivative · entry 11

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,054.263

Underlying: Common Stock · 336 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F5 · derivative.exercise_date: Portion of 2019 RSU Award accelerated to satisfy FICA taxes.

F5 · derivative.expiration_date: Portion of 2019 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · derivative · entry 10

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,390.263

Underlying: Common Stock · 187 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: Portion of 2018 RSU Award accelerated to satisfy FICA taxes.

F4 · derivative.expiration_date: Portion of 2018 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · derivative · entry 9

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,577.263

Underlying: Common Stock · 159 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F4 · derivative.exercise_date: Portion of 2018 RSU Award accelerated to satisfy FICA taxes.

F4 · derivative.expiration_date: Portion of 2018 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · derivative · entry 8

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,736.263

Underlying: Common Stock · 145 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: Portion of 2017 RSU Award accelerated to satisfy FICA taxes.

F3 · derivative.expiration_date: Portion of 2017 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · derivative · entry 7

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 31,881.263

Underlying: Common Stock · 120 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.

F3 · derivative.exercise_date: Portion of 2017 RSU Award accelerated to satisfy FICA taxes.

F3 · derivative.expiration_date: Portion of 2017 RSU Award accelerated to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · nonDerivative · entry 6

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,009.132

F2 · kind: Shares used to satisfy FICA taxes.

SEC source: 0001127602-19-034665 · form4.xml · nonDerivative · entry 5

BAGSHAW SETH H · CIK 0001192439 · Sr. VP, CFO & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,956.132

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.