STOCK TITAN

Tandem Diabetes (TNDM) exec gains shares via RSU vesting and ESPP

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

Rhea-AI Filing Summary

Tandem Diabetes Care EVP & Chief Administrative Officer Susan Morrison reported a series of routine equity compensation transactions in company stock. She acquired 9,523 shares of common stock through the vesting and conversion of restricted stock units and 1,336 shares through the employee stock purchase plan at $10.90 per share.

To cover tax obligations on these vestings, 2,724 shares were withheld by the company, and no shares were sold on the open market. After these transactions, Morrison directly holds 43,708 shares of common stock.

Positive

  • None.

Negative

  • None.
Insider Morrison Susan
Role EVP & Chief Admin. Officer
Type Security Shares Price Value
Exercise Restricted Stock Unit 1,503 $0.00 --
Exercise Restricted Stock Unit 1,097 $0.00 --
Exercise Restricted Stock Unit 6,923 $0.00 --
Exercise Common Stock 1,503 $0.00 --
Tax Withholding Common Stock 430 $12.82 $6K
Exercise Common Stock 1,097 $0.00 --
Tax Withholding Common Stock 314 $12.82 $4K
Exercise Common Stock 6,923 $0.00 --
Tax Withholding Common Stock 1,980 $12.82 $25K
Grant/Award Common Stock 1,336 $10.90 $15K
Holdings After Transaction: Restricted Stock Unit — 0 shares (Direct, null); Common Stock — 44,138 shares (Direct, null)
Footnotes (1)
  1. 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. 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, 2025, through May 15, 2026. This transaction is also exempt under Rule 16b-3(c). 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). 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. 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. Awarded on May 23, 2024 pursuant to the 2023 Plan. 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. Awarded on May 30, 2025 pursuant to the 2023 Plan. RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2026, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.
RSU shares acquired 9,523 shares Common stock from RSU exercises on May 15, 2026
ESPP shares acquired 1,336 shares at $10.90 Employee Stock Purchase Plan ending May 15, 2026
Shares withheld for taxes 2,724 shares at $12.82 Tax withholding on RSU vesting, no market sale
Shares held after transactions 43,708 shares Direct common stock ownership following Form 4 events
RSU exercise transactions 3 transactions, 9,523 shares Derivative exercises coded M on May 15, 2026
Tax withholding transactions 3 transactions, 2,724 shares Code F dispositions for tax liabilities
Restricted Stock Unit financial
"security_title": "Restricted Stock Unit""
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.
Employee Stock Purchase Plan financial
"Amended and Restated 2013 Employee Stock Purchase Plan (ESPP)"
An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.
Rule 16b-3(c) regulatory
"This transaction is also exempt under Rule 16b-3(c)."
An SEC rule that lets corporate insiders avoid automatic "short‑swing" profit recovery when they buy or sell their company’s stock under a pre‑approved, written plan that meets specific conditions. For investors, it matters because it clarifies when insider trades are treated as routine, reducing legal uncertainty and helping distinguish trades made for ordinary compensation or pre‑planned reasons from those that might signal opportunistic or timely insider advantage.
tax withholding requirements financial
"Shares withheld by Tandem Diabetes Care Inc. to satisfy tax withholding requirements"
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.
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*
Morrison Susan

(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)
Director10% Owner
XOfficer (give title below)Other (specify below)
EVP & Chief Admin. Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026
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 Stock05/15/2026M1,503A$044,138D
Common Stock05/15/2026F(1)430D$12.8243,708D
Common Stock05/15/2026M1,097A$044,805D
Common Stock05/15/2026F(1)314D$12.8244,491D
Common Stock05/15/2026M6,923A$051,414D
Common Stock05/15/2026F(1)1,980D$12.8249,434D
Common Stock05/15/2026A(2)1,336A$10.950,770D
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)(4)05/15/2026M1,503 (5) (5)Common Stock1,503$00D
Restricted Stock Unit(6)(4)05/15/2026M1,097 (7) (7)Common Stock1,097$04,387D
Restricted Stock Unit(8)(4)05/15/2026M6,923 (9) (9)Common Stock6,923$013,845D
Explanation of Responses:
1. 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.
2. 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, 2025, through May 15, 2026. This transaction is also exempt under Rule 16b-3(c).
3. 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).
4. 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.
5. 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.
6. Awarded on May 23, 2024 pursuant to the 2023 Plan.
7. 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.
8. Awarded on May 30, 2025 pursuant to the 2023 Plan.
9. RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2026, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.
Remarks:
/s/ Shannon M. Hansen, Attorney-in-Fact for Susan M. Morrison05/19/2026
** 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 executive Susan Morrison report?

Susan Morrison reported routine equity compensation activity, including RSU vesting and an employee stock purchase. She acquired common shares through restricted stock unit conversions and the employee stock purchase plan, with some shares withheld to satisfy tax obligations rather than sold in the market.

Did Susan Morrison of TNDM buy or sell shares on the open market?

She did not sell shares on the open market. Shares labeled as dispositions were withheld by Tandem Diabetes Care to cover tax obligations related to vesting restricted stock units, according to the footnotes, meaning they were not discretionary market sales.

How many Tandem Diabetes (TNDM) shares did Susan Morrison acquire via RSUs?

She acquired 9,523 shares of common stock through the exercise and conversion of restricted stock units. These RSUs were granted under the company’s 2023 Long-Term Incentive Plan and vested based on scheduled quarterly installments described in the accompanying footnotes.

What price did Susan Morrison pay under the TNDM employee stock purchase plan?

Under Tandem Diabetes Care’s Amended and Restated 2013 Employee Stock Purchase Plan, she acquired 1,336 shares of common stock at $10.90 per share. The disclosed ESPP purchase period ran from November 18, 2025, through May 15, 2026, and the transaction is exempt under Rule 16b-3(c).

How many TNDM shares were withheld for Susan Morrison’s tax obligations?

A total of 2,724 Tandem Diabetes Care shares were withheld to satisfy tax withholding requirements related to RSU vesting. Footnotes clarify these F-code dispositions were for tax payments only, and no shares from this activity were sold into the open market.

What is Susan Morrison’s direct TNDM shareholding after these transactions?

Following the reported equity compensation and tax withholding entries, Susan Morrison directly holds 43,708 shares of Tandem Diabetes Care common stock. This figure reflects her updated ownership after the RSU conversions, ESPP acquisition, and company share withholdings for taxes.