# EDGAR Filing Document

**Accession Number:** 0001238935
**File Stem:** 0001438133-26-000073
**Filing Date:** 2026-5
**Character Count:** 9287
**Document Hash:** 1bd8a60621131b20dc9915379559bc39
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001438133-26-000073.hdr.sgml**: 20260522

**ACCESSION NUMBER**: 0001438133-26-000073

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 3

**CONFORMED PERIOD OF REPORT**: 20260520

**FILED AS OF DATE**: 20260522

**DATE AS OF CHANGE**: 20260522

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** TWOMEY CHRISTOPHER J
- **CENTRAL INDEX KEY:** 0001238935

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36189
- **FILM NUMBER:** 261013719

**MAIL ADDRESS:**
- **STREET 1:** 12400 HIGH BLUFF DRIVE
- **STREET 2:** 12400 HIGH BLUFF DRIVE
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92130
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** TANDEM DIABETES CARE INC
- **CENTRAL INDEX KEY:** 0001438133
- **STANDARD INDUSTRIAL CLASSIFICATION:** SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 204327508
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 12400 HIGH BLUFF DRIVE
- **CITY:** San Diego
- **STATE:** CA
- **ZIP:** 92130
- **BUSINESS PHONE:** 858-366-6900

**MAIL ADDRESS:**
- **STREET 1:** 12400 HIGH BLUFF DRIVE
- **CITY:** San Diego
- **STATE:** CA
- **ZIP:** 92130

## Ex-24

![](tndmsubstitutepowerofatt001.jpg)

SUBSTITUTE POWER OF ATTORNEY Pursuant to written powers of attorney (each, a "Power of Attorney") by the individuals listed below, the undersigned, Shannon M. Hansen, has been constituted and appointed the true and lawful attorney-in-fact of such individuals, with full power of substitution, to execute and file documents with the U.S. Securities and Exchange Commission pursuant to Section 16(a) of the Securities Exchange Act of 1934, as amended, with respect to equity securities of Tandem Diabetes Care, Inc. and with such further powers as specified in each Power of Attorney. Individual Date of Power of Attorney Dick P. Allen April 19, 2022 Sandra W. Beaver November 11, 2025 Ricky A. Carpenter April 21, 2022 Myoungil Cha June 15, 2022 Elizabeth A. Gasser April 19, 2022 Peyton R. Howell April 20, 2022 Jean-Claude Kyrillos June 21, 2024 Joao Malagueira June 15, 2022 Kathleen McGroddy-Goetz April 21, 2022 Susan M. Morrison April 21, 2022 Rebecca B. Robertson April 20, 2022 John F. Sheridan April 20, 2022 Rajwant S. Sodhi April 21, 2022 Christopher J. Twomey April 20, 2022 Leigh A. Vosseller April 20, 2022 In accordance with the authority granted under each Power of Attorney, including the power of substitution, the undersigned hereby appoints Jerilyn Laskie as a substitute attorney-in-fact, on behalf of the individuals listed above, with the full power of substitution, to exercise and execute all of the powers granted or conferred to the undersigned in each Power of Attorney. For the avoidance of doubt, the foregoing appointment shall not serve as a revocation of the powers granted to the undersigned herself in each Power of Attorney. This Substitute Power of Attorney shall remain in full force and effect unless and until revoked by the undersigned. IN WITNESS WHEREOF, the undersigned has caused this Substitute Power of Attorney to be executed as of May 20, 2026. /s/ Shannon M. Hansen Shannon M. Hansen, Attorney-in-Fact

------

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>TWOMEY CHRISTOPHER J<br><sub>(Last) (First) (Middle)</sub><br>12400 HIGH BLUFF DRIVE<br><sub>(Street)</sub><br>SAN DIEGO, CA 92130<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-05-20 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>TANDEM DIABETES CARE INC [ TNDM ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-05-21 |  | M |  | 8759 | A | $0 | 24434 | D |  |
| Common Stock |  |  |  |  |  |  |  | 5112 | I | See Footnote<sup>(1)</sup> |
| Common Stock |  |  |  |  |  |  |  | 7568 | I | See Footnotes<sup>(2)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Restricted Stock Unit | <sup>(3)</sup> | 2026-05-20 |  | A |  | 10220 |  | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 10220 | $0 | 10220 | D |  |
| Restricted Stock Unit | <sup>(3)</sup> | 2026-05-21 |  | M |  |  | 8759 | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 8759 | $0 | 0 | D |  |

---

### Footnotes:

(1) The securities are held by the Chris J. Twomey and Rebecca J. Twomey Family Trust UTD September 20, 2002.

(2) The securities are directly owned by Twomey Family Investments, LLC. The Reporting Person is co-manager of Twomey Family Investments, LLC and shares voting and investment power overthese securities held by Twomey Family Investments, LLC and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of suchsecurities held by Twomey Family Investments, LLC, except to the extent of his proportionate pecuniary interest therein.

(3) Each restricted stock units (RSU) represents a contingent right to receive either one share of the Issuers common stock or cash in lieu thereof, at the Issuers discretion, in accordance with the terms ofthe Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).

(4) RSU will vest on the one-year anniversary of the grant date, subject to the terms of the 2023 Plan.

(5) On May 21, 2025, the Reporting Person was granted 8,759 RSUs, all of which vested and converted into shares of the Issuers common stock on the one-year anniversary thereof in accordance withthe 2023 Plan.

**Remarks:**
Ex. 24:  Power of Attorney

**Signature:** /s/ Jerilyn Laskie, Attorney-in-Fact for Christopher J. Twomey  
**Date:** 2026-05-22

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**