MKS INC — Director's Dealing 2015

Feb 26, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2015-02-25

Reporting Person: Quirk Brian Charles (Sr. VP, Global Operations)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-02-25	Common Stock	M	2694.635	$35.83	Acquired	5974.635	Direct
2015-02-25	Common Stock	M	1981	—	Acquired	7955.635	Direct
2015-02-25	Common Stock	F	1520	$35.83	Disposed	6435.635	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-02-25	Restricted Stock Unit	$	M	2694.635	Disposed		Common Stock (2694.635)	Direct
2015-02-25	Restricted Stock Unit	$	M	1981	Disposed		Common Stock (1981)	Direct

Footnotes

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

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

F3: 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 commencing on the first anniversary of the grant date, with the exception of RSUs granted on or after February 15, 2015, in which case, the annual vesting date shall be (i) February 15th or (ii) the next business day if February 15th is not a business day.

F4: These RSUs vest in three equal annual installments commencing on the first anniversary of the grant date, with the exception of RSUs granted on or after February 15, 2015, in which case, the annual vesting date shall be (i) February 15th or (ii) the next business day if February 15th is not a business day.