MKS INC — Director's Dealing 2014

Jan 2, 2014

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2013-12-30

Reporting Person: BERLINGHIERI LEO (Former CEO and Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-12-30	Common Stock	M	36746.543	—	Acquired	145852.15	Direct
2013-12-30	Common Stock	M	54999.142	—	Acquired	200851.292	Direct
2013-12-30	Common Stock	F	43305	$29.69	Disposed	157546.292	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-12-30	Restricted Stock Unit	$	M	36746.543	Disposed		Common Stock (36746.543)	Direct
2013-12-30	Restricted Stock Unit	$	M	54999.142	Disposed		Common Stock (54999.142)	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: Mr. Berlinghieri resigned from the Company on December 30, 2013. Upon Mr. Berlinghieri's retirement, 100% of unvested RSUs vest per agreement with the Company, with the exception of the 2013 performance RSU which vests in 2014, subject to the Company's performance criteria.

F4: 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.

F5: The RSUs vest in equal annual installments over three years.