Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* COLELLA GERARD G	2. Issuer Name and Ticker or Trading Symbol MKS INSTRUMENTS INC [ MKSI ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below)
(Last) (First) (Middle) C/O MKS INSTRUMENTS, INC., 2 TECH DRIVE, SUITE 201	3. Date of Earliest Transaction (MM/DD/YYYY) 7/2/2020
(Street) ANDOVER, MA 01810 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	7/2/2020		M		8574.454	A	⁽¹⁾	10565.04	D
Common Stock	7/2/2020		M		7085.573	A	⁽¹⁾	17650.613	D
Common Stock	7/2/2020		M		6607	A	⁽¹⁾	24257.613	D
Common Stock	7/2/2020		M		6606.066	A	⁽¹⁾	30863.679	D
Common Stock	7/2/2020		M		5038	A	⁽¹⁾	35901.679	D
Common Stock	7/2/2020		M		5037.575	A	⁽¹⁾	40939.254	D
Common Stock	7/2/2020		M		7260.921	A	⁽¹⁾	48200.175	D
Common Stock	7/2/2020		M		7260.921	A	⁽¹⁾	55461.096	D
Common Stock	7/2/2020		M		7551.917	A	⁽¹⁾	63013.013	D
Common Stock	7/2/2020		M		7551.917	A	⁽¹⁾	70564.93	D
Common Stock	7/2/2020		M		7550.917	A	⁽¹⁾	78115.847	D
Common Stock	7/2/2020		F⁽²⁾		32316	D	$113.79	45799.847	D
Common Stock								40800	I	By The Gerald G. Colella 2018 Grantor Trust
Common Stock								44786	I	By The Gerald G. Colella Living Trust

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			8574.454	⁽³⁾⁽⁴⁾	⁽³⁾⁽⁴⁾	Common Stock	8574.454	⁽¹⁾	67550.807	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7085.573	⁽⁴⁾⁽⁵⁾	⁽⁴⁾⁽⁵⁾	Common Stock	7085.573	⁽¹⁾	60465.234	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			6607	⁽⁴⁾⁽⁶⁾	⁽⁴⁾⁽⁶⁾	Common Stock	6607	⁽¹⁾	53858.234	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			6606.066	⁽⁴⁾⁽⁷⁾	⁽⁴⁾⁽⁷⁾	Common Stock	6606.066	⁽¹⁾	47252.168	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			5038	⁽⁴⁾⁽⁸⁾	⁽⁴⁾⁽⁸⁾	Common Stock	5038	⁽¹⁾	42214.168	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			5037.575	⁽⁴⁾⁽⁹⁾	⁽⁴⁾⁽⁹⁾	Common Stock	5037.575	⁽¹⁾	37176.593	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7260.921	⁽⁴⁾⁽¹⁰⁾	⁽⁴⁾⁽¹⁰⁾	Common Stock	7260.921	⁽¹⁾	29915.672	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7260.921	⁽⁴⁾⁽¹¹⁾	⁽⁴⁾⁽¹¹⁾	Common Stock	7260.921	⁽¹⁾	22654.751	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7551.917	⁽⁴⁾⁽¹²⁾	⁽⁴⁾⁽¹²⁾	Common Stock	7551.917	⁽¹⁾	15102.834	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7551.917	⁽⁴⁾⁽¹³⁾	⁽⁴⁾⁽¹³⁾	Common Stock	7551.917	⁽¹⁾	7550.917	D
Restricted Stock Unit	⁽¹⁾	7/2/2020		M			7550.917	⁽⁴⁾⁽¹⁴⁾	⁽⁴⁾⁽¹⁴⁾	Common Stock	7550.917	⁽¹⁾	0	D

Explanation of Responses:
(1)	Each restricted stock unit represents the contingent right to receive one share of common stock of MKS Instruments, Inc.
(2)	Shares used to satisfy taxes. This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person.
(3)	These RSUs were awarded on February 15, 2017 and were subject to the achievement of performance criteria determined in the first year of grant. These RSUs were scheduled to vest on February 18, 2020.
(4)	On January 1, 2020, Mr. Colella retired from the Company and pursuant to the terms of his RSU Agreement, these RSUs fully vested on that date but were not distributable until July 2, 2020 in accordance with Internal Revenue Code Section 409A.
(5)	These RSUs were awarded on February 15, 2017. These RSUs were scheduled to vest on February 18, 2020.
(6)	These RSUs were awarded on February 15, 2018 and were subject to the achievement of performance criteria determined in the first year of grant. These RSUs were scheduled to vest on February 18, 2020.
(7)	These RSUs were awarded on February 15, 2018 and were subject to the achievement of performance criteria determined in the first year of grant. These RSUs were scheduled to vest on February 16, 2021.
(8)	These RSUs were awarded on February 15, 2018. These RSUs were scheduled to vest on February 18, 2020.
(9)	These RSUs were awarded on February 15, 2018. These RSUs were scheduled to vest on February 16, 2021.
(10)	These RSUs were awarded on February 15, 2019 and were subject to the achievement of performance criteria determined in the first year of grant. These RSUs were scheduled to vest on February 16, 2021.
(11)	These RSUs were awarded on February 15, 2019 and were subject to the achievement of performance criteria determined in the first year of grant. These RSUs were scheduled to vest on February 15, 2022.
(12)	These RSUs were awarded on February 15, 2019. These RSUs were scheduled to vest on February 18, 2020.
(13)	These RSUs were awarded on February 15, 2019. These RSUs were scheduled to vest on February 16, 2021.
(14)	These RSUs were awarded on February 15, 2019. These RSUs were scheduled to vest on February 15, 2022.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
COLELLA GERARD G C/O MKS INSTRUMENTS, INC. 2 TECH DRIVE, SUITE 201 ANDOVER, MA 01810	X