SEC Form 4 · accession 0001438133-26-000132
TANDEM DIABETES CARE INC · TNDM
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Leigh Vosseller
Officer — EVP & CHIEF FINANCIAL OFFICER
Period of report
Aug 15, 2026
Accepted (ET)
Aug 18, 2026 · 4:28 pm EDT
Rule 10b5-1 plan
box not checked
Issuer CIK
0001438133
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common Stock | Aug 15, 2026 | M | 1,496 | $0.00 | A | 50,895 | D | |
| Common Stock | Aug 15, 2026 | F | 537 | $22.72 | D | 50,358 | D | |
| Common Stock | Aug 15, 2026 | M | 2,624 | $0.00 | A | 52,982 | D | |
| Common Stock | Aug 15, 2026 | F | 942 | $22.72 | D | 52,040 | D | |
| Common StockF2 | holding | — | — | — | 25,580 | I | Leigh A. Vosseller Trust |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Restricted Stock UnitF3,F4,F5 | — | Aug 15, 2026 | M | 1,496 | D | — | — | Common Stock | 1,496 | 4,486 | D |
| Restricted Stock UnitF6,F4,F7 | — | Aug 15, 2026 | M | 2,624 | D | — | — | Common Stock | 2,624 | 18,368 | D |
Explanation of responses
- F1Shares withheld by the Issuer to satisfy tax withholding requirements upon the vesting of restricted stock units (RSUs). No shares were sold.
- F2The securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, of which Leigh Vosseller is the Trustee.
- F3Awarded on May 23, 2024 pursuant to the Tandem Diabetes Care Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).
- F4Each RSU represents a contingent right to receive either one share of common stock of the Issuer or cash in lieu thereof, at the Issuer's discretion, in accordance with the terms of the 2023 Plan.
- F5One-third of the RSUs granted on May 23, 2024 vested on May 15, 2025, with the remaining RSUs vesting in eight (8) equal quarterly installments thereafter, subject to the terms of the 2023 Plan.
- F6Awarded on May 30, 2025 pursuant to the 2023 Plan.
- F7One-third of the RSUs granted on May 30, 2025 vested on May 15, 2026, with the remaining RSUs vesting in eight (8) equal quarterly installments thereafter, subject to the terms of the 2023 Plan.