As of March 23, 2026, the three largest insider holders of MASI are Capital Management Lp Politan (Other, 4.59Mn shares), Joe E Kiani (Ceo And Chairman Of The Board, 603.92K shares), Joe E Kiani (Ceo And Chairman Of The Board, 42.73K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Capital Management Lp Politan | 0 | 4,589,648 | 29 Aug, 2025 | |
| Anand Sampath | Evp, Ops Clinical Research | 40,909 | 0 | 30 Jan, 2026 |
| Thomas Samuel Mcclenahan | Evp, Gen Counsel Corp Sec | 36,747 | 0 | 01 Mar, 2024 |
| Micah W Young | Evp Chief Financial Officer | 25,656 | 0 | 16 Mar, 2026 |
| Bilal Muhsin | Chief Operating Officer | 24,172 | 0 | 14 May, 2025 |
| Craig B Reynolds | 18,371 | 0 | 01 May, 2025 | |
| Blair Tripodi | Coo, Consumer Division | 13,818 | 0 | 25 Sep, 2025 |
| Catherine M. Szyman | Ceo | 7,605 | 0 | 16 Mar, 2026 |
| Julie Ann Shimer | 4,410 | 0 | 31 May, 2023 | |
| Adam Mikkelson | 4,108 | 0 | 31 May, 2023 | |
| Darlene J. S. Solomon | 1,790 | 0 | 01 May, 2025 | |
| Timothy J Scannell | 1,383 | 0 | 01 May, 2025 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 11 Mar, 2026 | Catherine M. Szyman | Common Stock | A | 2,101 | $0.00 | 8,674 | D | M |
| 11 Mar, 2026 | Micah W Young | Common Stock | A | 873 | $0.00 | 26,127 | D | M |
| 11 Mar, 2026 | Micah W Young | Common Stock | D | 471 | $175.47 | 25,656 | D | F |
| 11 Mar, 2026 | Catherine M. Szyman | Common Stock | D | 1,069 | $175.47 | 7,605 | D | F |
| 11 Mar, 2026 | Catherine M. Szyman | Restricted Stock Units | D | 2,101 | $0.00 | 6,306 | D | M |
| 11 Mar, 2026 | Micah W Young | Restricted Stock Units | D | 873 | $0.00 | 2,622 | D | M |
| 11 Mar, 2026 | Capital Management Lp Politan | Forward Sale Contract (obligation to sell) | A | 142,681 | - | 142,681 | I | J |
| 12 Mar, 2026 | Capital Management Lp Politan | Forward Sale Contract (obligation to sell) | A | 130,869 | - | 130,869 | I | J |
| 06 Mar, 2026 | Micah W Young | Restricted Stock Units | A | 17,671 | $0.00 | 17,671 | D | A |
| 06 Mar, 2026 | Catherine M. Szyman | Restricted Stock Units | A | 39,904 | $0.00 | 39,904 | D | A |
| 06 Mar, 2026 | Greg Allen Meehan | Restricted Stock Units | A | 8,550 | $0.00 | 8,550 | D | A |
| 06 Mar, 2026 | Anand Sampath | Restricted Stock Units | A | 6,840 | $0.00 | 6,840 | D | A |
| 27 Feb, 2026 | Micah W Young | Common Stock | A | 15,000 | $0.00 | 33,347 | D | A |
| 27 Feb, 2026 | Micah W Young | Common Stock | D | 8,093 | $175.35 | 25,254 | D | F |
| 27 Feb, 2026 | Micah W Young | Restricted Stock Units | D | 15,000 | $0.00 | 0 | D | M |
| 26 Feb, 2026 | Micah W Young | Common Stock | A | 2,034 | $0.00 | 19,470 | D | A |
| 26 Feb, 2026 | Micah W Young | Common Stock | D | 1,123 | $175.22 | 18,347 | D | F |
| 12 Feb, 2026 | Catherine M. Szyman | Common Stock | A | 11,141 | $132.96 | 11,141 | D | M |
| 12 Feb, 2026 | Catherine M. Szyman | Common Stock | D | 4,568 | $0.00 | 6,573 | D | F |
| 12 Feb, 2026 | Catherine M. Szyman | Restricted Stock Units | D | 11,141 | $0.00 | 22,283 | D | M |