ASGN Inc — Director's Dealing 2013

May 16, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ON ASSIGNMENT INC (ASGN)
CIK: 0000890564
Period of Report: 2013-05-14

Reporting Person: McGrath Emmett (Pres, Life Sciences &Allied HC)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-05-14	Common Stock	M	10000	$4.97	Acquired	129149	Direct
2013-05-14	Common Stock	S	10000	$26.5914	Disposed	119149	Direct
2013-05-14	Common Stock	M	15000	$6.38	Acquired	134149	Direct
2013-05-14	Common Stock	S	15000	$26.5914	Disposed	119149	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-05-14	Incentive Stock Option (right to buy)	$4.97	M	10000	Disposed	2014-08-30	Common Stock (10000)	Direct
2013-05-14	Non-Qualified Stock Option (right to buy)	$6.38	M	15000	Disposed	2018-01-02	Common Stock (15000)	Direct

Footnotes

F1: These options vest one-fourth of the total number of shares on August 30, 2005, and one forty-eighth of such amount with respect to each month thereafter.

F2: These options vest one forty-eighth after one month from the grant date, and one forty-eighth of such amount with respect to each month thereafter.