X0306 4 2015-11-13 0 0000874716 IDEXX LABORATORIES INC /DE IDXX 0001184149 AYERS JONATHAN W ONE IDEXX DRIVE WESTBROOK ME 04092 1 1 0 0 Chairman, President and CEO Common Stock 2015-11-13 4 M 0 20174 17.185 A 961640 D Common Stock 98000 I By Ayers Family Trust Non-Qualified Stock Option (right-to-buy) 17.185 2015-11-13 4 M 0 20174 D 2016-02-13 Common Stock 20174 0 D Includes 99 shares acquired under the IDEXX Laboratories, Inc. Employee Stock Purchase Plan on September 30, 2015. Grant of option to buy shares of IDEXX Laboratories, Inc. common stock that became exercisable as to 15,999 shares on February 14, 2010 and February 14, 2013, 16,000 shares on February 14, 2011 and February 14, 2012, and the remaining 13,091 shares on February 14, 2014, without giving effect to the 2-for-1 stock split of IDEXX Laboratories, Inc. common stock that occurred on June 15, 2015 (the "Stock Split"). The number of derivative securities reported as beneficially owned with respect to this option and its exercise price were adjusted to reflect the Stock Split. Not applicable. /s/ Lily J. Lu, Attorney-in-Fact for Jonathan W. Ayers 2015-11-13