ASGN Inc — Director's Dealing 2012

Feb 6, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON ASSIGNMENT INC (ASGN)
CIK: 0000890564
Period of Report: 2012-02-03

Reporting Person: Brouse Mark (President, Vista Staffing)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-02-03	Common Stock	A	4573	—	Acquired	155311	Direct
2012-02-03	Common Stock	D	1392	$12.19	Disposed	153919	Direct
2012-02-03	Common Stock	A	3504	—	Acquired	157423	Direct
2012-02-03	Common Stock	D	1066	$12.19	Disposed	156357	Direct
2012-02-03	Common Stock	A	3047	—	Acquired	159404	Direct
2012-02-03	Common Stock	D	927	$12.19	Disposed	158477	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	8500	Indirect

Footnotes

F1: 2009 Performance Award - 3rd of three installments granted 3/8/11. Goal Acheived; Based on Adjusted EBITDA

F2: Executive officer elected to satisfy tax withholding obligations upon vesting by having On Assignment, Inc. withhold a number of vested shares equal to that of the employee's tax liability.

F3: 2010 Performance Award - 2nd of three installments granted 3/8/11. Goal Acheived; Based on Adjusted EBITDA

F4: 2011 Performance Award - 1st of three installments granted 3/8/11. Goal acheived; Based on Adjusted EBITDA