X0306 4 2023-02-08 0 0000874716 IDEXX LABORATORIES INC /DE IDXX 0001630353 Underberg Sharon E. ONE IDEXX DRIVE WESTBROOK ME 04092 0 1 0 0 EVP, GC & Corp. Secretary Common Stock 3041.9949 D Non-Qualified Stock Option (right-to-buy) 497.43 2023-02-08 4 A 0 4949 A 2033-02-07 Common Stock 4949 4949 D Incentive Stock Option (right-to-buy) 497.43 2023-02-08 4 A 0 201 A 2033-02-07 Common Stock 201 201 D Restricted Stock Unit 2023-02-08 4 A 0 704 A Common Stock 704 3207 D Includes a total of 55 shares acquired under the IDEXX Laboratories, Inc. Employee Stock Purchase Plan on March 31, 2022, June 30, 2022, September 30, 2022 and December 31, 2022. Grant of option to buy shares of Issuer common stock that becomes exercisable in four annual installments beginning February 14, 2024. Grant of option to buy shares of Issuer common stock that becomes exercisable in one installment on February 14, 2027. Each restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer common stock. This RSU grant vests in four annual installments, beginning February 14, 2024. Not applicable. /s/ Lily J. Lu, Attorney-in-Fact for Sharon E. Underberg 2023-02-10