X0304 4 2012-02-03 0 0000890564 ON ASSIGNMENT INC ASGN 0001388670 McGowan Michael ON ASSIGNMENT, INC. 26745 MALIBU HILLS ROAD CALABASAS CA 91301 0 1 0 0 CEO - Oxford Global Resources Common Stock 2012-02-03 4 A 0 5879 0 A 314635 D Common Stock 2012-02-03 4 D 0 1866 12.19 D 312769 D Common Stock 2012-02-03 4 A 0 7928 0 A 320697 D Common Stock 2012-02-03 4 D 0 2517 12.19 D 318180 D Common Stock 2012-02-03 4 A 0 6894 0 A 325074 D Common Stock 2012-02-03 4 D 0 2188 12.19 D 322886 D Common Stock 5000 I by Trust 2009 Performance Award - 3rd of three installments granted 3/8/11. Goal Acheived; Based on Adjusted EBITDA 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. 2010 Performance Award - 2nd of three installments granted 3/8/11. Goal Acheived; Based on Adjusted EBITDA 2011 Performance Award - 1st of three installments granted 3/8/11. Goal acheived; Based on Adjusted EBITDA By: Power of Attorney, James L. Brill, CFO For: Michael J. McGowan 2012-02-06