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Tandem Diabetes (TNDM) director Twomey reports RSU grant and 8,759-unit vesting

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Tandem Diabetes Care director Christopher J. Twomey reported equity compensation activity. On May 20, 2026, he received a grant of 10,220 Restricted Stock Units (RSUs), each representing a contingent right to one share of common stock or cash under the 2023 Long-Term Incentive Plan.

On May 21, 2026, a prior grant of 8,759 RSUs (awarded on May 21, 2025) fully vested and converted into common shares, increasing his directly held common stock to 24,434 shares. Additional common shares are held indirectly by the Chris J. Twomey and Rebecca J. Twomey Family Trust and by Twomey Family Investments, LLC, where he shares voting and investment power and disclaims beneficial ownership except for his proportionate pecuniary interest.

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Insider TWOMEY CHRISTOPHER J
Role null
Type Security Shares Price Value
Exercise Restricted Stock Unit 8,759 $0.00 --
Exercise Common Stock 8,759 $0.00 --
Grant/Award Restricted Stock Unit 10,220 $0.00 --
holding Common Stock -- -- --
holding Common Stock -- -- --
Holdings After Transaction: Restricted Stock Unit — 0 shares (Direct, null); Common Stock — 24,434 shares (Direct, null); Common Stock — 5,112 shares (Indirect, See Footnote)
Footnotes (1)
  1. The securities are held by the Chris J. Twomey and Rebecca J. Twomey Family Trust UTD September 20, 2002. 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 over these 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 such securities held by Twomey Family Investments, LLC, except to the extent of his proportionate pecuniary interest therein. 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 of the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan). RSU will vest on the one-year anniversary of the grant date, subject to the terms of the 2023 Plan. 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 with the 2023 Plan.
RSUs vested 8,759 units RSUs granted May 21, 2025 and vested on one-year anniversary
New RSU grant 10,220 units Grant to director on May 20, 2026 under 2023 Plan
Direct common shares after transactions 24,434 shares Common stock directly held by Christopher J. Twomey after RSU vesting
Family trust indirect holding 7,568 shares Common stock held by Chris J. Twomey and Rebecca J. Twomey Family Trust
Family LLC indirect holding 5,112 shares Common stock held by Twomey Family Investments, LLC; proportional pecuniary interest only
Restricted Stock Unit financial
"Each restricted stock units (RSU) represents a contingent right to receive either one share of the Issuers common stock or cash in lieu thereof"
A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.
derivative security financial
"transaction_code_description": "Exercise or conversion of derivative security""
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.
beneficial ownership financial
"may be deemed to have indirect beneficial ownership of such shares"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
pecuniary interest financial
"disclaims beneficial ownership of such securities held by Twomey Family Investments, LLC, except to the extent of his proportionate pecuniary interest therein"
Long-Term Incentive Plan financial
"in accordance with the terms of the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan"
A long-term incentive plan is a company program that pays executives or employees with stock, options, or cash tied to multi-year performance goals, where the rewards become theirs only after meeting conditions over time. Think of it as a delayed bonus or retirement-style reward that aligns employees’ interests with shareholders by encouraging them to boost long-term value; investors watch these plans because they affect pay costs, share dilution and management incentives.
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
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*
TWOMEY CHRISTOPHER J

(Last)(First)(Middle)
12400 HIGH BLUFF DRIVE

(Street)
SAN DIEGO CALIFORNIA 92130

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
TANDEM DIABETES CARE INC [ TNDM ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock05/21/2026M8,759A$024,434D
Common Stock5,112ISee Footnote(1)
Common Stock7,568ISee Footnotes(2)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Unit(3)05/20/2026A10,220 (4) (4)Common Stock10,220$010,220D
Restricted Stock Unit(3)05/21/2026M8,759 (5) (5)Common Stock8,759$00D
Explanation of Responses:
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 over these 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 such securities 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 of the 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 with the 2023 Plan.
Remarks:
Ex. 24: Power of Attorney
/s/ Jerilyn Laskie, Attorney-in-Fact for Christopher J. Twomey05/22/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did TNDM director Christopher Twomey report?

Director Christopher J. Twomey reported equity compensation activity, not open-market trading. A prior grant of 8,759 RSUs vested into common stock, and he received a new grant of 10,220 RSUs under Tandem Diabetes Care’s 2023 Long-Term Incentive Plan.

How many Tandem Diabetes (TNDM) shares does Christopher Twomey hold directly after these transactions?

After the reported RSU vesting, Christopher J. Twomey directly holds 24,434 shares of Tandem Diabetes Care common stock. This reflects conversion of 8,759 vested RSUs into shares, in addition to his existing directly held position disclosed in the Form 4.

What RSU grant did Tandem Diabetes (TNDM) give Christopher Twomey on May 20, 2026?

On May 20, 2026, Christopher J. Twomey received a grant of 10,220 Restricted Stock Units. Each RSU represents a contingent right to one Tandem Diabetes Care common share or cash, subject to vesting under the company’s 2023 Long-Term Incentive Plan.

When did Christopher Twomey’s 8,759 Tandem Diabetes RSUs vest and convert to shares?

The 8,759 RSUs granted to Christopher J. Twomey on May 21, 2025 vested on the one-year anniversary of that date. Upon vesting, they converted into shares of Tandem Diabetes Care common stock in accordance with the 2023 Long-Term Incentive Plan.

How are Christopher Twomey’s indirect Tandem Diabetes (TNDM) holdings structured?

Indirect holdings are reported through the Chris J. Twomey and Rebecca J. Twomey Family Trust and Twomey Family Investments, LLC. Twomey shares voting and investment power over LLC-held shares and disclaims beneficial ownership except for his proportionate pecuniary interest there.