X0306 4 2016-01-01 0 0000874716 IDEXX LABORATORIES INC /DE IDXX 0001219445 MCKEON BRIAN P ONE IDEXX DRIVE WESTBROOK ME 04092 0 1 0 0 EVP, CFO, and Treasurer Common Stock 2016-01-01 4 M 0 2820 0.00 A 31710 D Common Stock 2016-01-01 4 F 0 1129 72.92 D 30581 D Restricted Stock Unit 2016-01-01 4 M 0 2820 D Common Stock 2820 14508 D The number of securities reported reflects a 2-for-1 stock split in the form of a 100% stock dividend on IDEXX Laboratories, Inc. common stock paid on June 15, 2015 (the "Stock Split"). Reflects the closing price of Issuer's common stock on the NASDAQ market on December 31, 2015. These restricted stock units are part of a grant made to the reporting person on January 1, 2014 that have vested. Each restricted stock unit represents a contingent right to receive one share of IDEXX Laboratories, Inc. common stock. The restricted stock units vest in five equal annual installments, beginning on the first anniversary date of the date of grant. The number of restricted stock units reported was adjusted to reflect the Stock Split. Not applicable. /s/ Lily J. Lu, Attorney-in-Fact for Brian P. McKeon 2016-01-05