MKSI

SEC source: 0001127602-18-006769 · form4.xml · nonDerivative · entry 3

Lee John Tseng-Chung · CIK 0001414656 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,224.846

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: 0001127602-18-006769 · form4.xml · nonDerivative · entry 2

Lee John Tseng-Chung · CIK 0001414656 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,006.846

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: 0001127602-18-006769 · form4.xml · nonDerivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,932.988

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: 0001127602-18-006763 · form4.xml · derivative · entry 15

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,424.686

Underlying: Common Stock · 2,954 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.

F10 · 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.

F10 · 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: 0001127602-18-006763 · form4.xml · derivative · entry 14

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,063.299

Underlying: Common Stock · 3,574 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 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.

F9 · 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: 0001127602-18-006763 · form4.xml · derivative · entry 13

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 13,378.686

Underlying: Common Stock · 4,515 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 vest in three equal annual installments commencing on February 15, 2017, 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 vest in three equal annual installments commencing on February 15, 2017, 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: 0001127602-18-006763 · form4.xml · derivative · entry 12

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,637.299

Underlying: Common Stock · 6,914 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 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, 2017, 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 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, 2017, 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: 0001127602-18-006763 · form4.xml · derivative · entry 11

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,893.686

Underlying: Common Stock · 3,782.518 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 vest in three equal annual installments commencing on February 15, 2016, 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 vest in three equal annual installments commencing on February 15, 2016, 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: 0001127602-18-006763 · form4.xml · derivative · entry 10

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,551.299

Underlying: Common Stock · 5,234.128 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 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, 2016, 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 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, 2016, 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: 0001127602-18-006763 · form4.xml · derivative · entry 9

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 16,275.271

Underlying: Common Stock · 5,850.585 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.

F4 · 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.

F4 · 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: 0001127602-18-006763 · form4.xml · derivative · entry 8

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 24,189.312

Underlying: Common Stock · 10,126.013 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 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.

F3 · 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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 7

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 28,068.966

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

SEC source: 0001127602-18-006763 · form4.xml · nonDerivative · entry 6

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 38,739.966

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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 5

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,785.966

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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 4

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 32,211.966

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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 3

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 27,696.966

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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 2

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,782.966

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: 0001127602-18-006763 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,000.448

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: 0001127602-18-006760 · form4.xml · derivative · entry 16

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,809.156

Underlying: Common Stock · 7,385 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.

F10 · 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.

F10 · 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: 0001127602-18-006760 · form4.xml · derivative · entry 15

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,527.117

Underlying: Common Stock · 8,936 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 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.

F9 · 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: 0001127602-18-006760 · form4.xml · derivative · entry 14

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 33,194.156

Underlying: Common Stock · 11,038 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 vest in three equal annual installments commencing on February 15, 2017, 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 vest in three equal annual installments commencing on February 15, 2017, 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: 0001127602-18-006760 · form4.xml · derivative · entry 13

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,463.117

Underlying: Common Stock · 15,653 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 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, 2017, 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 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, 2017, 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: 0001127602-18-006760 · form4.xml · derivative · entry 12

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 44,232.156

Underlying: Common Stock · 9,456.794 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 vest in three equal annual installments commencing on February 15, 2016, 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 vest in three equal annual installments commencing on February 15, 2016, 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: 0001127602-18-006760 · form4.xml · derivative · entry 11

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,116.117

Underlying: Common Stock · 12,213.298 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 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, 2016, 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 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, 2016, 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: 0001127602-18-006760 · form4.xml · derivative · entry 10

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 41,560.731

Underlying: Common Stock · 15,751.575 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.

F4 · 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.

F4 · 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: 0001127602-18-006760 · form4.xml · derivative · entry 9

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 63,905.155

Underlying: Common Stock · 30,378.038 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 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.

F3 · 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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 7

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,293.742

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

SEC source: 0001127602-18-006760 · form4.xml · nonDerivative · entry 6

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 69,706.742

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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 5

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 62,321.742

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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 4

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 53,385.742

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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 3

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 42,347.742

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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 2

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 26,694.742

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: 0001127602-18-006760 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,237.948

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: 0001127602-18-006252 · form4.xml · nonDerivative · entry 1

HANLEY PETER · CIK 0001185717 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,772.102

SEC source: 0001127602-18-005401 · form4.xml · derivative · entry 1

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,282.07

Underlying: Common Stock · 1,499.262 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 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.

F3 · 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: 0001127602-18-005398 · form4.xml · derivative · entry 1

Quirk Brian Charles · CIK 0001600515 · Sr. VP, Global Operations

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,259.401

Underlying: Common Stock · 1,070.901 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 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.

F3 · 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: 0001127602-18-005394 · form4.xml · derivative · entry 1

Lee John Tseng-Chung · CIK 0001414656 · Sr. VP & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 23,152.631

Underlying: Common Stock · 2,141.802 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 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.

F3 · 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: 0001127602-18-005396 · form4.xml · derivative · entry 1

Abrams John R · CIK 0001600505 · Sr. VP, Global Sales & Service

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,324.908

Underlying: Common Stock · 1,285.081 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 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.

F3 · 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: 0001127602-18-005392 · form4.xml · derivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 29,785.427

Underlying: Common Stock · 2,570.163 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 and thereafter vest in three equal 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.

F3 · 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 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: 0001127602-18-005390 · form4.xml · derivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 70,329.415

Underlying: Common Stock · 6,425.406 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.

F2 · kind: This transaction reflects the forfeiture of RSUs due to performance criteria.

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 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.

F3 · 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: 0001127602-18-004253 · form4.xml · nonDerivative · entry 1

Quirk Brian Charles · CIK 0001600515 · Sr. VP, Global Operations

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,862.883

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

SEC source: 0001127602-18-001724 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Gerald G. Colella Living Trust

Disclosed balance after: 46,296

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $95.30 to $96.60. 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: 0001127602-18-001427 · form4.xml · nonDerivative · entry 1

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

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,766.32

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.

F2 · price: This transaction was executed in multiple trades at prices ranging from $102.00 to $102.15. 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: 0001127602-17-034964 · form4.xml · derivative · entry 11

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 5,911 shares

Expires 2019-04-12

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.

F4 · derivative.exercise_date: The stock appreciation right became fully vested on March 31, 2015.

SEC source: 0001127602-17-034964 · form4.xml · nonDerivative · entry 8

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F2 · kind: Shares have been withheld in satisfaction of reporting person's tax withholding obligations resulting from the exercise of stock appreciation rights.

SEC source: 0001127602-17-034964 · form4.xml · nonDerivative · entry 7

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,207

F1 · kind: Reflects the disposition of shares to the issuer deemed to occur upon the exercise of a stock appreciation right.

SEC source: 0001127602-17-034964 · form4.xml · nonDerivative · entry 6

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,889

SEC source: 0001127602-17-034964 · form4.xml · nonDerivative · entry 5

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 5,911

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.

SEC source: 0001127602-17-034793 · form4.xml · nonDerivative · entry 1

COLELLA GERARD G · CIK 0001256715 · Director · CEO, President, Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Gerald G. Colella Living Trust

Disclosed balance after: 56,296

F1 · price: This transaction was executed in multiple trades at prices ranging from $95.200 to $95.350. 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: 0001127602-17-034964 · form4.xml · derivative · entry 10

Werth Dennis L · CIK 0001550572 · Sr. VP, Business Units

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 4,199 shares

Expires 2018-05-17

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.

F3 · derivative.exercise_date: The stock appreciation right became fully vested on March 31, 2014.