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: BAGSHAW SETH H (Vice President, CFO, Treasurer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2014-02-24	Common Stock	M	3115.427	—	Acquired	28537.054	Direct
2014-02-24	Common Stock	M	2119	—	Acquired	25421.627	Direct
2014-02-24	Common Stock	F	1705	$30.02	Disposed	26832.054	Direct
2014-02-25	Common Stock	M	5051.941	—	Acquired	35597.995	Direct
2014-02-25	Common Stock	M	3714	—	Acquired	30546.054	Direct
2014-02-25	Common Stock	F	2854	$29.77	Disposed	32743.995	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2014-02-24	Restricted Stock Unit	$	M	3115.427	Disposed		Common Stock (3115.427)	Direct
2014-02-24	Restricted Stock Unit	$	M	2119	Disposed		Common Stock (2119)	Direct
2014-02-25	Restricted Stock Unit	$	M	5051.941	Disposed		Common Stock (5051.941)	Direct
2014-02-25	Restricted Stock Unit	$	M	3714	Disposed		Common Stock (3714)	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.