July 19, 2019 Brian P. McKeon Executive Vice President, Chief Financial Officer and Treasurer IDEXX Laboratories, Inc. One IDEXX Drive Westbrook Maine 04092 Re: IDEXX Laboratories, Inc. Form 10-K for the Fiscal Year Ended December 31, 2018 Filed February 15, 2019 File No. 000-19271 Dear Mr. McKeon: We have reviewed your filing and have the following comment. In our comment, we ask you to provide us with information so we may better understand your disclosure. Please respond to this comment within 10 business days by providing the requested information or advise us as soon as possible when you will respond. If you do not believe our comment applies to your facts and circumstances, please tell us why in your response. After reviewing your response to this comment, we may have additional comments. Form 10-K for the Fiscal Year Ended December 31, 2018 Notes to Consolidated Financial Statements Note 3: Revenue Recognition, page F-18 1. On page F-19 you disclose that diagnostic products and accessories revenues (including consumables) are recognized and invoiced at the time of shipment, which is when the customer obtains control of the product based on legal title transfer. On page 35, you disclose that SediVue Dx consumables are charged to customers upon utilization, which you refer to as pay-per-run. Please tell us your policy for recognizing revenue for SediVue Dx consumables and how your recognition conforms with your disclosed recognition policy. In your response, tell us why you do not charge a customer until after utilization and clarify when title passes. Reference for us the authoritative literature relied upon to support your accounting. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Brian P. McKeon IDEXX Laboratories, Inc. July 19, 2019 Page 2 You may contact Mark Brunhofer at (202) 551-3638 or Jim Rosenberg at (202) 551- 3679 with any questions. FirstName LastNameBrian P. McKeon Sincerely, Comapany NameIDEXX Laboratories, Inc. Division of Corporation Finance July 19, 2019 Page 2 Office of Healthcare & Insurance FirstName LastName