IDEXX LABORATORIES INC DE

Reconciliation of Non-GAAP Financial Measures

We report our results in accordance with generally accepted accounting principles in the United States, or GAAP. We use certain non-GAAP financial measures in this Proxy Statement that exclude or adjust certain items to supplement our consolidated results presented in accordance with GAAP or as part of our executive compensation program. Our reconciliation of these non-GAAP financial measures to the most directly comparable financial measure calculated and presented in accordance with GAAP is included in this Appendix.

While we believe that these non-GAAP financial measures are useful in evaluating our business, this information should be considered as supplemental in nature and should not be considered in isolation or as a substitute for the related financial information prepared in accordance with GAAP. In addition, these non-GAAP financial measures may not be the same as similarly titled measures reported by other companies.

After-Tax Return on Invested Capital, Excluding Cash and Investments (ROIC)

After-tax return on invested capital, excluding cash and investments (ROIC), is a non-GAAP financial measure that represents our after-tax income from operations, divided by our average invested capital, excluding cash and investments, using the beginning and ending balance sheet values. ROIC, after-tax income from operations and average invested capital, excluding cash and investments, are not measures of financial performance under GAAP and should be considered in addition to, and not as replacements of or superior measures to, return on assets, net income, total assets or other financial measures reported in accordance with GAAP. We believe that reporting ROIC provides useful information to investors for evaluating the efficiency and effectiveness of our use of capital. It is also a metric used in our Executive Incentive Plan.

APPENDIX A + + +

In this Proxy Statement, we report our ROIC for 2023. The reconciliation of this non-GAAP financial measure is as follows:

1. After-tax income from operations represents income from operations reduced by our reported effective tax rate of 20.4% for the year ended December 31, 2023. Refer to Note 14 to our consolidated financial statements included in our 2023 Annual Report on Form 10-K for information on our effective tax rate.

2. Average invested capital, excluding cash and investments, represents the average of the amount of total invested capital, excluding cash and investments, as of December 31, 2023 and December 31, 2023.

Comparable EPS Growth

Comparable EPS growth is a non-GAAP financial measure that represents the percentage change in earnings per share (diluted), as compared to the same period for the prior year, net of the impact of changes in foreign currency exchange rates and excluding the tax benefits of share-based compensation activity under ASU 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” (ASU 2016-09) and non-recurring or unusual items (if any). Comparable EPS growth should be considered in addition to, and not as a replacement of or a superior measure to, earnings per share (diluted) growth reported in accordance with GAAP. We believe that reporting comparable EPS growth provides useful information to investors by facilitating better period-over-period comparisons of our fundamental earnings per share performance by excluding items that vary independent of performance and providing greater transparency regarding a key metric used by management.

• • • APPENDIX A

In this Proxy Statement, we report the comparable EPS growth for 2023, which excludes the impact of tax benefits of share-based compensation activity under ASU 2016-09 and changes in foreign currency exchange rates. We estimate the net impact of changes in foreign currency exchange rates on EPS results by restating results to the average exchange rates or exchange rate assumptions for the comparative period, which includes adjusting for the estimated impacts of foreign currency hedging transactions and certain impacts on our effective tax rates.

The reconciliation of this non-GAAP financial measure is as follows:

Amounts presented may not recalculate due to rounding.

Comparable Operating Margin Improvement

Comparable operating margin improvement is a non-GAAP financial measure that represents the percentage change in operating margin, as compared to the same period for the prior year, and excludes the impact of changes in foreign currency exchange rates and non-recurring or unusual items (if any). Comparable operating margin improvement should be considered in addition to, and not as a replacement of or a superior measure to, operating margin improvement reported in accordance with GAAP. We believe that reporting comparable operating margin improvement provides useful information to investors by facilitating better period-over-period comparisons of our fundamental operating margin performance by excluding items that vary independent of performance and providing greater transparency regarding a key metric used by management.

In this Proxy Statement, we report the comparable operating margin improvement for 2023, which excludes changes in foreign currency exchange rates in 2023. We estimate the net impact of changes in foreign currency exchange rates on operating margin results by restating results to the average exchange rates or exchange rate assumptions for the comparative period, which includes adjusting for the estimated impacts of foreign currency hedging transactions and certain impacts on our effective tax rates.

APPENDIX A + + +

The reconciliation of this non-GAAP financial measure is as follows:

1. Amounts presented may not recalculate to constant currency operating margin or constant currency margin improvement due to rounding.

Free Cash Flow and the Ratio of Free Cash Flow to Net Income

Free cash flow is a non-GAAP financial measure and means, with respect to a measurement period, the cash generated from operations during that period, reduced by the Company’s investments in property and equipment. The ratio of free cash flow to net income is a non-GAAP financial measure that is defined as free cash flow, with respect to a measurement period, divided by net income for the same period. Free cash flow and the ratio of free cash flow to net income should each be considered in addition to, and not as a replacement of or a superior measure to, net cash provided by operating activities. We believe that reporting free cash flow provides useful information to investors because free cash flow indicates the cash the operations of the business are generating after appropriate reinvestment for recurring investments in property and equipment that are required to operate the business. We believe that reporting the ratio of free cash flow to net income provides useful information to investors because it provides a useful way for investors to compare free cash flow over time.

In this Proxy Statement, we report our free cash flow and the ratio of free cash flow to net income for 2023. The reconciliation of these non-GAAP financial measures is as follows:

• • • APPENDIX A

Organic Revenue Growth

Organic revenue growth is a non-GAAP financial measure that represents the percentage change in revenue, as compared to the same period for the prior year, net of the impact of changes in foreign currency exchange rates, certain business acquisitions and divestitures. Organic revenue growth should be considered in addition to, and not as a replacement of or a superior measure to, revenue growth reported in accordance with GAAP. We believe that reporting organic revenue growth provides useful information to investors by facilitating easier comparisons of our revenue performance with prior and future periods and to the performance of our peers.

We exclude from organic revenue growth the effect of changes in foreign currency exchange rates because these changes are not under management’s control, are subject to volatility and can obscure underlying business trends. We calculate the impact on revenue resulting from changes in foreign currency exchange rates by applying the difference between weighted average exchange rates during 2023 and 2022 to foreign-currency-denominated revenues for 2022.

We also exclude from organic revenue growth the effect of certain business acquisitions and divestitures because the nature, size and number of these transactions can vary dramatically from period to period, and because they either require or generate cash as an inherent consequence of the transaction, and therefore can also obscure underlying business and operating trends. We consider acquisitions to be a business when all three elements of inputs, processes and outputs are present, consistent with ASU 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business.” In a business combination, if substantially all the fair value of the assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets, we do not consider these assets to be a business. A typical acquisition that we do not consider a business is a customer list asset acquisition, which does not have all elements necessary to operate a business, such as employees or infrastructure. We believe that the efforts required to convert and retain these acquired customers are similar in nature to our existing customer base and therefore are included in organic revenue growth. The percentage change in revenue resulting from acquisitions represents revenues during the current year period, limited to the initial twelve months from the date of acquisition, that are directly attributable to business acquisitions.

In this Proxy Statement, we report the Company’s organic revenue growth and CAG Diagnostics recurring revenue organic growth in 2023. The reconciliation of these non-GAAP financial measures is as follows:

1. Amounts presented may not recalculate due to rounding.

THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting:

The Notice and Proxy Statement and Annual Report are available at www.idexxproxymaterials.com.

E58088-P19475

IDEXX LABORATORIES, INC.Proxy for the 2024 Annual Meeting of ShareholdersTo Be Held on May 6, 2024THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF THE COMPANY

The undersigned, revoking all prior proxies, hereby appoint(s) Lawrence D. Kingsley and Sharon E. Underberg, and each of them, with full power of substitution, as proxies to represent and vote, as designated on the reverse side of this ballot, all shares of Common Stock of IDEXX Laboratories, Inc. (the “Company”) which the undersigned would be entitled to vote at the 2024 Annual Meeting to be held at 4:30 PM EDT on Monday, May 6, 2024 at www.virtualshareholdermeeting.com/IDXX2024.This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors’ recommendations and in accordance with the judgment of the proxies upon any other matter that may properly come before the meeting and any adjournment or postponement thereof.

Continued and to be signed on reverse side