MKS INC — Director's Dealing 2014

Feb 27, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2014-02-24

Reporting Person: COLELLA GERARD G (Director, CEO, President, Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2014-02-24	Common Stock	M	4283.587	—	Acquired	7608.079	Direct
2014-02-24	Common Stock	M	2914	—	Acquired	10522.079	Direct
2014-02-24	Common Stock	F	2344	$30.02	Disposed	8178.079	Direct
2014-02-25	Common Stock	M	6735.588	—	Acquired	14913.667	Direct
2014-02-25	Common Stock	M	4952	—	Acquired	19865.667	Direct
2014-02-25	Common Stock	F	3805	$29.77	Disposed	16060.667	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2014-02-24	Restricted Stock Unit	$	M	4283.587	Disposed		Common Stock (4283.587)	Direct
2014-02-24	Restricted Stock Unit	$	M	2914	Disposed		Common Stock (2914)	Direct
2014-02-25	Restricted Stock Unit	$	M	6735.588	Disposed		Common Stock (6735.588)	Direct
2014-02-25	Restricted Stock Unit	$	M	4952	Disposed		Common Stock (4952)	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 the grant and thereafter vests in equal annual installments over three years.

F4: The RSUs vest in equal annual installments over three years.