As of September 12, 2026, Idexx Laboratories's top three insider holders are Jonathan W Ayers (Director, 419.57K shares), Jonathan W Ayers (Chairman, President Ceo, 122.61K shares), Jonathan Jay Mazelsky (President And Ceo, 83.80K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Jonathan W Ayers | Director | 0 | 419,574 | 419,574 | 63.3% | 09 Sep, 2024 |
| 2 | Jonathan Jay Mazelsky | President And Ceo | 83,803 | 0 | 83,803 | 12.6% | 02 Mar, 2026 |
| 3 | Brian P Mckeon | Evp, Cfo And Treasurer | 31,550 | 0 | 31,550 | 4.8% | 18 Feb, 2025 |
| 4 | Giovani Twigge | Senior Vice President | 20,329 | 0 | 20,329 | 3.1% | 25 Feb, 2022 |
| 5 | Nimrata Hunt | Executive Vice President | 18,141 | 0 | 18,141 | 2.7% | 05 Mar, 2026 |
| 6 | Michael G Erickson | Executive Vice President | 15,092 | 0 | 15,092 | 2.3% | 19 Feb, 2026 |
| 7 | James F Polewaczyk | Executive Vice President | 10,711 | 0 | 10,711 | 1.6% | 07 Mar, 2024 |
| 8 | George Fennell | Executive Vice President | 10,433 | 0 | 10,433 | 1.6% | 02 Jun, 2026 |
| 9 | Lawrence D Kingsley | Director | 9,568 | 0 | 9,568 | 1.4% | 09 Sep, 2026 |
| 10 | Michael Lane | Executive Vice President | 8,024 | 0 | 8,024 | 1.2% | 17 Feb, 2026 |
| 11 | Kathy V Turner | Senior Vice President | 7,380 | 0 | 7,380 | 1.1% | 17 Feb, 2023 |
| 12 | Sharon E. Underberg | Evp, Gc Corporate Secretary | 7,138 | 0 | 7,138 | 1.1% | 05 Mar, 2026 |
| 13 | Andrew Emerson | Evp, Cfo And Treasurer | 4,421 | 0 | 4,421 | 0.7% | 24 Aug, 2026 |
| 14 | Daniel M Junius | Director | 3,561 | 0 | 3,561 | 0.5% | 11 May, 2026 |
| 15 | Michael Schreck | Executive Vice President | 3,089 | 0 | 3,089 | 0.5% | 17 Feb, 2026 |
| 16 | Michael Perkins Johnson | Executive Vice President | 2,795 | 0 | 2,795 | 0.4% | 17 Feb, 2026 |
| 17 | Stuart Essig | Director | 2,236 | 0 | 2,236 | 0.3% | 08 May, 2025 |
| 18 | Martin Alexander Smith | Executive Vice President | 2,157 | 0 | 2,157 | 0.3% | 17 Feb, 2026 |
| 19 | Sophie V. Vandebroek | Director | 905 | 0 | 905 | 0.1% | 11 May, 2026 |
| 20 | Asha Collins | Director | 779 | 0 | 779 | 0.1% | 08 May, 2024 |
| 21 | M Anne Szostak | Director | 519 | 0 | 519 | 0.1% | 11 May, 2026 |
| 22 | Joseph L Hooley | Director | 325 | 0 | 325 | 0.0% | 03 Aug, 2026 |
| 23 | Irene Chang Britt | Director | 208 | 0 | 208 | 0.0% | 08 May, 2024 |
| 24 | Bruce L. Claflin | Director | 161 | 0 | 161 | 0.0% | 20 May, 2024 |
| 25 | Karen Peacock | Director | 102 | 0 | 102 | 0.0% | 11 May, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 04 Sep, 2026 | Lawrence D Kingsley | Director | Acquired M | 2,203 | $114.17 | $251.52K | 11,771 | Direct |
| 04 Sep, 2026 | Lawrence D Kingsley | Director | Disposed S | 2,203 | $532.08 | $1.17Mn | 9,568 | Direct |
| 04 Sep, 2026 | Lawrence D Kingsley | Director | Disposed M | 2,203 | — | — | 0 | Direct |
| 20 Aug, 2026 | Andrew Emerson | Evp, Cfo And Treasurer | Acquired M | 265 | $178.26 | $47.24K | 4,507 | Direct |
| 20 Aug, 2026 | Andrew Emerson | Evp, Cfo And Treasurer | Disposed F | 86 | $0.00 | $0 | 4,421 | Direct |
| 20 Aug, 2026 | Andrew Emerson | Evp, Cfo And Treasurer | Disposed M | 265 | — | — | 925 | Direct |
| 30 Jul, 2026 | Joseph L Hooley | Director | Acquired A | 49 | $558.80 | $27.38K | 325 | Direct |
| 01 Jun, 2026 | George Fennell | Executive Vice President | Acquired M | 639 | $0.00 | $0 | 10,717 | Direct |
| 01 Jun, 2026 | George Fennell | Executive Vice President | Disposed F | 284 | $566.79 | $160.97K | 10,433 | Direct |
| 01 Jun, 2026 | George Fennell | Executive Vice President | Disposed M | 639 | — | — | 0 | Direct |
| 12 May, 2026 | Sophie V. Vandebroek | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Irene Chang Britt | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Karen Peacock | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Joseph L Hooley | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Daniel M Junius | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Stuart Essig | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Sam Samad | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Lawrence D Kingsley | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Bruce L. Claflin | Director | Acquired A | 525 | $0.00 | $0 | 525 | Direct |
| 12 May, 2026 | Lawrence D Kingsley | Director | Acquired A | 168 | $0.00 | $0 | 168 | Direct |