Vosseller Leigh

SEC source: 0001438133-25-000083 · wk-form4_1747692327.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 28,584

F1 · acquired: The reporting person is voluntarily reporting the acquisition of shares of common stock pursuant to the Tandem Diabetes Care, Inc. Amended and Restated 2013 Employee Stock Purchase Plan (ESPP), for the ESPP purchase period of November 18, 2024, through May 15, 2025. This transaction is also exempt under Rule 16b-3(c).

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · derivative · entry 7

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 5,523 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · security: Awarded on May 25, 2022 pursuant to the 2013 Plan.

F4 · derivative.exercise_price: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F4 · derivative.exercise_date: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F4 · derivative.expiration_date: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · derivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,380 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · security: Awarded on May 18, 2021 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F4 · derivative.exercise_price: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F4 · derivative.exercise_date: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F4 · derivative.expiration_date: Each PSU represents a contingent right to receive one share of the Company common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2024 (the Measurement Date). The number of shares issued may range from 0% to 200% of the base grant amount, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · nonDerivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,225

F1 · kind: Shares withheld by Tandem Diabetes Care, Inc. (the Company) to satisfy tax withholding requirements on vesting of performance stock units (PSU). No shares were sold.

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · nonDerivative · entry 3

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 29,252

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,729

F1 · kind: Shares withheld by Tandem Diabetes Care, Inc. (the Company) to satisfy tax withholding requirements on vesting of performance stock units (PSU). No shares were sold.

SEC source: 0001438133-25-000039 · wk-form4_1740694537.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 24,223

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · derivative · entry 10

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,515

Underlying: Common Stock · 1,504 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · security: Awarded on May 25, 2023 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).

F9 · derivative.exercise_price: Each 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.

F10 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F10 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · derivative · entry 9

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 474

Underlying: Common Stock · 474 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · security: Awarded on May 25, 2022 pursuant to the 2013 Plan.

F4 · derivative.exercise_price: Each 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.

F7 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F7 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · derivative · entry 8

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 162

Underlying: Common Stock · 163 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · security: Awarded on May 18, 2021 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F4 · derivative.exercise_price: Each 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.

F5 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

F5 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,843

F1 · kind: 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.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 5

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,461

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,957

F1 · kind: 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.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 3

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,152

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,678

F1 · kind: 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.

SEC source: 0001438133-25-000016 · wk-form4_1740089218.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,745

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · derivative · entry 10

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,019

Underlying: Common Stock · 1,503 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · security: Awarded on May 25, 2023 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).

F9 · derivative.exercise_price: Each 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.

F10 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F10 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · derivative · entry 9

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 948

Underlying: Common Stock · 475 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · security: Awarded on May 25, 2022 pursuant to the 2013 Plan.

F4 · derivative.exercise_price: Each 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.

F7 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F7 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · derivative · entry 8

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 325

Underlying: Common Stock · 162 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · security: Awarded on May 18, 2021 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F4 · derivative.exercise_price: Each 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.

F5 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

F5 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,582

F1 · kind: 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.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 5

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,119

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,616

F1 · kind: 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.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 3

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,786

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,311

F1 · kind: 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.

SEC source: 0001438133-24-000211 · wk-form4_1732054947.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,369

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · derivative · entry 10

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,522

Underlying: Common Stock · 1,503 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F8 · security: Awarded on May 25, 2023 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).

F9 · derivative.exercise_price: Each 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.

F10 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F10 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · derivative · entry 9

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,423

Underlying: Common Stock · 474 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · security: Awarded on May 25, 2022 pursuant to the 2013 Plan.

F4 · derivative.exercise_price: Each 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.

F7 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

F7 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · derivative · entry 8

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 487

Underlying: Common Stock · 163 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · security: Awarded on May 18, 2021 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F4 · derivative.exercise_price: Each 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.

F5 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

F5 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,207

F1 · kind: 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.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 5

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,744

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,241

F1 · kind: 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.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 3

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,411

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,937

F1 · kind: 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.

SEC source: 0001438133-24-000187 · wk-form4_1724113854.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,996

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000143 · wk-form4_1716936302.xml · derivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 406 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · security: Awarded on May 27, 2020 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F8 · derivative.exercise_price: Each 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.

F9 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on the one year anniversary of the grant date, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

F9 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on the one year anniversary of the grant date, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter, subject to the terms of the 2013 Plan.

SEC source: 0001438133-24-000143 · wk-form4_1716936302.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,833

F1 · kind: 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.

SEC source: 0001438133-24-000143 · wk-form4_1716936302.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,978

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000143 · wk-form4_1716936302.xml · derivative · entry 5

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,946

Underlying: Common Stock · 17,946 shares

Expires not disclosed

F3 · security: Awarded on May 23, 2024 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan (the 2023 Plan).

F6 · derivative.exercise_price: Each performance stock unit (PSU) represents a contingent right to receive one share of Tandem Diabetes Care, Inc. (the Company) common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2026 (the Measurement Date). The number of shares issued may range from 0% to 200% of the amount specified above, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F6 · derivative.exercise_date: Each performance stock unit (PSU) represents a contingent right to receive one share of Tandem Diabetes Care, Inc. (the Company) common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2026 (the Measurement Date). The number of shares issued may range from 0% to 200% of the amount specified above, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

F6 · derivative.expiration_date: Each performance stock unit (PSU) represents a contingent right to receive one share of Tandem Diabetes Care, Inc. (the Company) common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2026 (the Measurement Date). The number of shares issued may range from 0% to 200% of the amount specified above, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.

SEC source: 0001438133-24-000143 · wk-form4_1716936302.xml · derivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 17,946

Underlying: Common Stock · 17,946 shares

Expires not disclosed

F3 · security: Awarded on May 23, 2024 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan (the 2023 Plan).

F4 · derivative.exercise_price: Each restricted stock unit (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.

F5 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2025, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F5 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2025, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · derivative · entry 11

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,025

Underlying: Common Stock · 6,012 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F9 · security: Awarded on May 25, 2023 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan (the 2023 Plan).

F10 · derivative.exercise_price: Each 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.

F11 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F11 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · derivative · entry 10

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,897

Underlying: Common Stock · 474 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F7 · security: Awarded on May 25, 2022 pursuant to the 2013 Plan.

F5 · derivative.exercise_price: Each 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.

F8 · derivative.exercise_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

F8 · derivative.expiration_date: RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2023, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · derivative · entry 9

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 650

Underlying: Common Stock · 162 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · security: Awarded on May 18, 2021 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F5 · derivative.exercise_price: Each 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.

F6 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

F6 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 5/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 7

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 18,572

F2 · kind: 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.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 6

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,718

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 5

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,706

F2 · kind: 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.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,876

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 3

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,402

F2 · kind: 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.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 2

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,460

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001438133-24-000099 · wk-form4_1715982384.xml · nonDerivative · entry 1

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,298

F1 · shares: The reporting person is voluntarily reporting the acquisition of shares of common stock pursuant to the Tandem Diabetes Care, Inc. Amended and Restated 2013 Employee Stock Purchase Plan (ESPP), for the ESPP purchase period of November 16, 2023 through May 15, 2024. This transaction is also exempt under Rule 16b-3(c).

SEC source: 0001438133-24-000036 · wk-form4_1709244773.xml · derivative · entry 4

Vosseller Leigh · CIK 0001726322 · EVP & CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 406

Underlying: Common Stock · 407 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · security: Awarded on May 27, 2020 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

F4 · derivative.exercise_price: Each 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.

F5 · derivative.exercise_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on May 27, 2021, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

F5 · derivative.expiration_date: RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on May 27, 2021, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.