ROEDER DOUGLAS A

SEC source: 0001270735-26-000016 · form4-10052026_041008.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 172,671.2843

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,740.80 divided by $9.96, the closing price of Issuer's common stock on the Nasdaq Global Select Market on October 1, 2026.

SEC source: 0001270735-26-000014 · form4-08202026_100815.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 171,191.2843

F1 · price: The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $8.95 to $8.99 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001270735-26-000012 · form4-07022026_040705.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 157,238

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,745.36 divided by $5.36, the closing price of Issuer's common stock on the Nasdaq Global Select Market on July 1, 2026.

SEC source: 0001270735-26-000010 · form4-05212026_050507.xml · derivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,574

Underlying: Common Stock · 13,574 shares

Expires 2036-05-19

F3 · derivative.exercise_date: Represents a stock option grant pursuant to the Policy. The options vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

SEC source: 0001270735-26-000010 · form4-05212026_050507.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 154,487

F1 · shares: Represents a restricted stock unit ("RSU") grant pursuant to the Issuer's non-employee director compensation policy (the "Policy"). The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001270735-26-000008 · form4-05132026_040501.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 144,635

SEC source: 0001270735-26-000006 · form4-04022026_050408.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 121,949

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,749.70 divided by $6.65, the closing price of Issuer's common stock on the Nasdaq Global Select Market on April 1, 2026.

SEC source: 0001270735-26-000004 · form4-03162026_020341.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 119,731

SEC source: 0001270735-26-000002 · form4-01052026_050105.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 102,231

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,746.06 divided by $5.89, the closing price of Issuer's common stock on the Nasdaq Global Select Market on January 2, 2026.

SEC source: 0001270735-25-000006 · form4-11102025_071110.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 99,727

F1 · balance_after: Effective October 17, 2025, the Issuer effected a 1-for-20 reverse stock split of the Issuer's common stock. The number of securities reported herein have been adjusted to reflect the reverse stock split.

SEC source: 0001270735-25-000004 · form4-10032025_041020.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,694,540

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,749.88 divided by $0.413, the closing price of Issuer's common stock on the NYSE American on October 1, 2025.

SEC source: 0001415889-25-019314 · form4-07032025_040725.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,658,826

F1 · kind: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,749.81 divided by $0.476, the closing price of Issuer's common stock on the NYSE American on July 1, 2025.

SEC source: 0001415889-25-014716 · form4-05282025_040513.xml · derivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 157,234

Underlying: Common Stock · 157,234 shares

Expires 2035-05-22

F3 · derivative.exercise_date: Represents a stock option grant pursuant to the Policy. The options vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

SEC source: 0001415889-25-014716 · form4-05282025_040513.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,627,839

F1 · shares: Represents a restricted stock unit ("RSU") grant pursuant to the Issuer's non-employee director compensation policy (the "Policy"). The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001415889-25-009962 · form4-04032025_040431.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,516,453

F1 · shares: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,749.48 divided by $0.6649, the closing price of Issuer's common stock on the NYSE American on April 1, 2025.

SEC source: 0001415889-25-000646 · form4-01032025_110133.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,494,270

F1 · shares: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,749.56 divided by $0.473, the closing price of Issuer's common stock on the NYSE American on January 2, 2025.

SEC source: 0001415889-24-029478 · form4-12162024_091222.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,413,087

F2 · price: The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.4975 to $0.4999 inclusive.

SEC source: 0001415889-24-029987 · form4a-12202024_101250.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,463,087

F1 · shares: The original Form 4 inadvertently omitted shares that were purchased. This amendment updates the number of shares purchased and the number of shares beneficially owned following the transaction.

F2 · price: The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.4975 to $0.50495 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

F1 · balance_after: The original Form 4 inadvertently omitted shares that were purchased. This amendment updates the number of shares purchased and the number of shares beneficially owned following the transaction.

SEC source: 0001415889-24-029478 · form4-12162024_091222.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,388,087

F1 · price: The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.4061 to $0.41 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnotes (1) and (2).

SEC source: 0001415889-24-024542 · form4-10032024_121007.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,088,087

F1 · shares: This common stock was issued to the Reporting Person pursuant to the Issuer's non-employee director compensation policy in lieu of quarterly retainer fees. The number of shares of common stock is equal to $14,750 divided by $0.3371, the closing price of Issuer's common stock on the NYSE American on October 1, 2024.

SEC source: 0001415889-24-014550 · form4-05242024_080548.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,044,332

F1 · shares: Represents a restricted stock unit ("RSU") grant pursuant to the Issuer's non-employee director compensation policy. The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001209191-23-047859 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 807,988

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $0.5303 to $0.5399, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001209191-23-036664 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 507,988

SEC source: 0001209191-23-031060 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 307,988

F1 · shares: Represents a restricted stock unit ("RSU") grant pursuant to the Issuer's non-employee director compensation policy. The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001209191-22-032984 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 160,040

F1 · shares: Represents a restricted stock unit ("RSU") grant pursuant to the Issuer's non-employee director compensation policy. The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the Reporting Person's continuous service through such vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001438133-22-000093 · wf-form4_165300468964694.xml · derivative · entry 4

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,205 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 restricted stock (RSU) unit represents a contingent right to receive one share of common stock of the Company.

F5 · derivative.exercise_date: Shares will vest on the one year anniversary of the grant date, subject to the terms of the 2013 Plan.

F5 · derivative.expiration_date: Shares will vest on the one year anniversary of the grant date, subject to the terms of the 2013 Plan.

SEC source: 0001438133-22-000093 · wf-form4_165300468964694.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,205

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: 0001104659-21-128113 · tm2130602d1_4.xml · nonDerivative · entry 4

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,766

F1 · kind: Represents a pro rata distribution, not for additional consideration, by Delphi BioInvestments VIII, L.P. ("DB VIII") and Delphi Ventures VIII, L.P. ("DV VIII") to their respective partners, and by Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of each of DB VIII and DV VIII, to its members and assignees, as applicable. This distribution was made pursuant to a Rule 10b5-1 distribution plan.

F5 · kind: This transaction is being voluntarily reported, reflects a change in form of beneficial ownership of the Reporting Person and is exempt from Section 16 pursuant to Rule 16a-13 under the Securities Exchange Act of 1934.

F4 · ownership.nature: The shares are held directly by The Roeder Family Trust dated 5/29/08, of which the Reporting Person is trustee.

SEC source: 0001104659-21-128113 · tm2130602d1_4.xml · nonDerivative · entry 3

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 1,892

F1 · kind: Represents a pro rata distribution, not for additional consideration, by Delphi BioInvestments VIII, L.P. ("DB VIII") and Delphi Ventures VIII, L.P. ("DV VIII") to their respective partners, and by Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of each of DB VIII and DV VIII, to its members and assignees, as applicable. This distribution was made pursuant to a Rule 10b5-1 distribution plan.

F5 · kind: This transaction is being voluntarily reported, reflects a change in form of beneficial ownership of the Reporting Person and is exempt from Section 16 pursuant to Rule 16a-13 under the Securities Exchange Act of 1934.

F3 · ownership.nature: Shares are held directly by DMP. The Reporting Person is a managing member of DMP. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DMP, and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001104659-21-128113 · tm2130602d1_4.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 13,460

F1 · kind: Represents a pro rata distribution, not for additional consideration, by Delphi BioInvestments VIII, L.P. ("DB VIII") and Delphi Ventures VIII, L.P. ("DV VIII") to their respective partners, and by Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of each of DB VIII and DV VIII, to its members and assignees, as applicable. This distribution was made pursuant to a Rule 10b5-1 distribution plan.

F5 · kind: This transaction is being voluntarily reported, reflects a change in form of beneficial ownership of the Reporting Person and is exempt from Section 16 pursuant to Rule 16a-13 under the Securities Exchange Act of 1934.

F3 · ownership.nature: Shares are held directly by DMP. The Reporting Person is a managing member of DMP. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DMP, and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001104659-21-128113 · tm2130602d1_4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

F1 · kind: Represents a pro rata distribution, not for additional consideration, by Delphi BioInvestments VIII, L.P. ("DB VIII") and Delphi Ventures VIII, L.P. ("DV VIII") to their respective partners, and by Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of each of DB VIII and DV VIII, to its members and assignees, as applicable. This distribution was made pursuant to a Rule 10b5-1 distribution plan.

F5 · kind: This transaction is being voluntarily reported, reflects a change in form of beneficial ownership of the Reporting Person and is exempt from Section 16 pursuant to Rule 16a-13 under the Securities Exchange Act of 1934.

F2 · ownership.nature: Shares are held directly by DB VIIII and DV VIII. The Reporting Person is a managing member of DMP. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DB VIII and DV VIII, and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001209191-21-053558 · doc4.xml · derivative · entry 6

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 86,930 shares

Expires 2029-05-29

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 · derivative.exercise_date: Fully vested and exercisable.

SEC source: 0001209191-21-053558 · doc4.xml · derivative · entry 5

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 128,817 shares

Expires 2027-05-23

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 · derivative.exercise_date: Fully vested and exercisable.

SEC source: 0001209191-21-053558 · doc4.xml · nonDerivative · entry 4

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,483

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.47 to $3.57 inclusive.

SEC source: 0001209191-21-053558 · doc4.xml · nonDerivative · entry 3

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 276,230

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: 0001209191-21-053558 · doc4.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 189,300

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: 0001209191-21-053558 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 60,483

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.64 to $3.675 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1) and (2).

SEC source: 0001438133-21-000104 · wf-form4_162465291006595.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 992,222

F1 · kind: The reported transaction was a transfer of shares from Mr. Roeder's direct holdings to Delphi Management Partners VIII, L.L.C.

F2 · ownership.nature: The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of Delphi Ventures VIII, L.P. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by Delphi Ventures VIII, L.P. and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by Delphi Ventures VIII, L.P., except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001438133-21-000104 · wf-form4_162465291006595.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: The reported transaction was a transfer of shares from Mr. Roeder's direct holdings to Delphi Management Partners VIII, L.L.C.

SEC source: 0001438133-21-000086 · wf-form4_162259011764091.xml · derivative · entry 4

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,892 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: Granted pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan (the 2013 Plan).

F4 · derivative.exercise_price: Each restricted stock unit (RSU) represents a contingent right to receive one share of common stock of the Company.

F5 · kind: This RSU award was granted on May 27, 2020. 100% of the RSU vested on May 27, 2021.

F6 · derivative.exercise_date: RSU vest as to one-hundred percent (100%) of the total number of shares subject to the RSU on 5/27/2021.

F6 · derivative.expiration_date: RSU vest as to one-hundred percent (100%) of the total number of shares subject to the RSU on 5/27/2021.

SEC source: 0001438133-21-000086 · wf-form4_162259011764091.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1,892

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: 0001209191-21-036419 · doc4.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 185,825

F3 · shares: Represents an RSU grant pursuant to the Issuer's non-employee director compensation policy. The RSUs vest in full on the earlier of the one year anniversary of the date of grant or the next annual stockholders meeting, subject to the reporting person's continuous service through such vesting date.

F4 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.

SEC source: 0001209191-21-036419 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 125,342

F1 · kind: Represents the number of shares sold by the Reporting Person to satisfy the Reporting Person's tax obligations resulting from the settlement of vested restricted stock units ("RSUs") on May 25, 2021. The sales were effected pursuant to a "sell-to-cover" arrangement adopted in accordance with Rule 10b5-1 on March 14, 2021.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.87 to $1.96 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0001104659-21-070131 · tm2117184d1_4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

F1 · price: This transaction was executed in multiple trades at prices ranging from $2.08 to $2.085, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F2 · ownership.nature: Shares held directly by Delphi BioInvestments VIII, L.P. ("DBI VIII"). The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of DBI VIII. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DBI VIII and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by DBI VIII, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001438133-21-000064 · wf-form4_162161698900856.xml · derivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,205

Underlying: Common Stock · 2,205 shares

Expires not disclosed

F1 · 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").

F2 · 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 2013 Plan.

F3 · derivative.exercise_date: RSU will vest on the one-year anniversary of the grant date, subject to the terms of the 2013 Plan.

F3 · derivative.expiration_date: RSU will vest on the one-year anniversary of the grant date, subject to the terms of the 2013 Plan.

SEC source: 0001104659-21-049878 · tm2112899d1_4.xml · nonDerivative · entry 4

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 652

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan entered into on March 10, 2021.

F3 · price: This transaction was executed in multiple trades at prices ranging from $2.02 to $2.37, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F5 · ownership.nature: Shares held directly by Delphi BioInvestments VIII, L.P. ("DBI VIII"). The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of DBI VIII. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DBI VIII and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by DBI VIII, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001104659-21-049878 · tm2112899d1_4.xml · nonDerivative · entry 3

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan entered into on March 10, 2021.

F3 · price: This transaction was executed in multiple trades at prices ranging from $2.02 to $2.37, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F4 · ownership.nature: Shares held directly by Delphi Ventures VIII, L.P. ("DV VIII"). The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of DV VIII. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DV VIII and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by DV VIII, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001104659-21-049878 · tm2112899d1_4.xml · nonDerivative · entry 2

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 48,232

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan entered into on March 10, 2021.

F2 · price: This transaction was executed in multiple trades at prices ranging from $2.30 to $2.565, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F5 · ownership.nature: Shares held directly by Delphi BioInvestments VIII, L.P. ("DBI VIII"). The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of DBI VIII. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DBI VIII and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by DBI VIII, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001104659-21-049878 · tm2112899d1_4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 4,845,399

F1 · kind: This transaction was effected pursuant to a Rule 10b5-1 trading plan entered into on March 10, 2021.

F2 · price: This transaction was executed in multiple trades at prices ranging from $2.30 to $2.565, inclusive. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F4 · ownership.nature: Shares held directly by Delphi Ventures VIII, L.P. ("DV VIII"). The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of DV VIII. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by DV VIII and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by DV VIII, except to the extent of his proportionate pecuniary interest therein.

SEC source: 0001209191-20-043420 · doc4.xml · nonDerivative · entry 1

ROEDER DOUGLAS A · CIK 0001270735 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 273,077

F1 · shares: Represents a restricted stock unit ("RSU") grant. The RSUs vest in eight equal installments with the first installment vesting on July 21, 2020 and the remaining RSUs vesting in six month increments commencing on November 15, 2020, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date.

F2 · price: Each RSU represents a contingent right to receive one share of the Issuer's common stock.