X0508 4 2025-12-15 0 0001438133 TANDEM DIABETES CARE INC TNDM 0001513889 Carpenter Rick 12400 HIGH BLUFF DRIVE SAN DIEGO CA 92130 0 1 0 0 Chief Technology Officer 0 Common Stock 2025-12-15 4 M 0 406 0 A 24459 D Common Stock 2025-12-15 4 F 0 207 22.11 D 24252 D Restricted Stock Unit 2025-12-15 4 M 0 406 0 D Common Stock 406 0 D Shares withheld by Tandem Diabetes Care Inc. (the Company) to satisfy tax withholding requirements on vesting of restricted stock units (RSU). No shares were sold. Awarded on December 15, 2021 pursuant to the Tandem Diabetes Care Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan). 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 2013 Plan. RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 12/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter. /s/ Shannon M. Hansen, Attorney-in-Fact for Rick A. Carpenter 2025-12-17