TNDM: Financial results

Item 2.02 Results of Operations and Financial Condition . On November 5, 2026, Tandem Diabetes Care, Inc. issued a press release announcing its f inancial results for the quarter ended September 30, 2026. This press release has been furnished as Exhibit 99.1 to this report and is incorporated herein by reference. The information under this Item 2.02 and Exhibit 99.1 hereto is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the Exchange Act), or otherwise subject to the liabilities of that section, nor shall they be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits. Number Description 99.1 Press release of Tandem Diabetes Care, Inc. dated November 5, 2026. 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). 2 SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Tandem Diabetes Care, Inc. By: /s/ SHANNON M. HANSEN Shannon M. Hansen Executive Vice President, Chief Legal, Privacy & Compliance Officer and Secretary Date: November 5, 2026 3