IDXX's three largest insider shareholders as of March 23, 2026 are Jonathan W Ayers (Director, 158.26K shares), Jonathan Jay Mazelsky (President And Ceo, 83.80K shares), Brian P Mckeon (Evp, Cfo And Treasurer, 31.55K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Jonathan W Ayers | 35,651 | 122,605 | 09 Sep, 2024 | |
| Jonathan Jay Mazelsky | President And Ceo | 83,803 | 0 | 02 Mar, 2026 |
| Brian P Mckeon | Evp, Cfo And Treasurer | 31,550 | 0 | 18 Feb, 2025 |
| Giovani Twigge | Senior Vice President | 20,329 | 0 | 25 Feb, 2022 |
| Nimrata Hunt | Executive Vice President | 18,141 | 0 | 05 Mar, 2026 |
| Michael G Erickson | Executive Vice President | 15,092 | 0 | 19 Feb, 2026 |
| James F Polewaczyk | Executive Vice President | 10,711 | 0 | 07 Mar, 2024 |
| George Fennell | Executive Vice President | 10,078 | 0 | 17 Feb, 2026 |
| Lawrence D Kingsley | 9,229 | 0 | 08 May, 2025 | |
| Sophie V. Vandebroek | 0 | 8,173 | 05 May, 2023 | |
| Michael Lane | Executive Vice President | 8,024 | 0 | 17 Feb, 2026 |
| Kathy V Turner | Senior Vice President | 7,380 | 0 | 17 Feb, 2023 |
| Sharon E. Underberg | Evp, Gc Corporate Secretary | 7,138 | 0 | 05 Mar, 2026 |
| Andrew Emerson | Evp, Cfo And Treasurer | 4,222 | 0 | 17 Feb, 2026 |
| Daniel M Junius | 3,304 | 0 | 14 May, 2025 | |
| Michael Schreck | Executive Vice President | 3,089 | 0 | 17 Feb, 2026 |
| Michael Perkins Johnson | Executive Vice President | 2,795 | 0 | 17 Feb, 2026 |
| Stuart Essig | 2,236 | 0 | 08 May, 2025 | |
| Martin Alexander Smith | Executive Vice President | 2,157 | 0 | 17 Feb, 2026 |
| Bruce L. Claflin | 0 | 1,560 | 01 Dec, 2021 | |
| Asha Collins | 779 | 0 | 08 May, 2024 | |
| Sophie V. Vandebroek | 648 | 0 | 19 Feb, 2026 | |
| M Anne Szostak | 262 | 259 | 26 Aug, 2025 | |
| Irene Chang Britt | 208 | 0 | 08 May, 2024 | |
| Bruce L. Claflin | 161 | 0 | 20 May, 2024 | |
| Joseph L Hooley | 75 | 0 | 03 Feb, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 03 Mar, 2026 | Sharon E. Underberg | Common Stock | A | 197 | $505.53 | 7,138 | D | M |
| 03 Mar, 2026 | Nimrata Hunt | Common Stock | D | 1,758 | $634.57 | 18,141 | D | S |
| 03 Mar, 2026 | Sharon E. Underberg | Incentive Stock Option (right-to-buy) | D | 197 | - | 0 | D | M |
| 12 Feb, 2026 | Michael G Erickson | Non-Qualified Stock Option (right-to-buy) | A | 13,667 | $0.00 | 13,667 | D | A |
| 12 Feb, 2026 | Michael G Erickson | Incentive Stock Option (right-to-buy) | A | 162 | $0.00 | 162 | D | A |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | A | 23,326 | $141.60 | 106,932 | D | M |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,281 | $650.67 | 105,651 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,095 | $651.49 | 104,556 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,669 | $652.49 | 102,887 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,171 | $653.68 | 101,716 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,111 | $654.63 | 100,605 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,488 | $655.85 | 99,117 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,343 | $656.85 | 97,774 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 2,860 | $657.84 | 94,914 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 3,660 | $658.92 | 91,254 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 2,859 | $659.75 | 88,395 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,200 | $661.10 | 87,195 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 1,000 | $662.16 | 86,195 | D | S |
| 26 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | D | 2,589 | $663.04 | 83,606 | D | S |
| 27 Feb, 2026 | Jonathan Jay Mazelsky | Common Stock | A | 197 | $505.53 | 83,803 | D | M |