TMUS: Financial results

Item 2.02 — Results of Operations and Financial Condition On October 28, 2026, T-Mobile US, Inc. (the “Company”) issued a press release announcing the financial and operating results of the Company for the quarter ended September 30, 2026. The text of the press release and accompanying Investor Factbook are furnished as Exhibits 99.1 and 99.2 and incorporated herein by reference. The information in Item 2.02 to this Current Report on Form 8-K, including Exhibits 99.1 and 99.2 , is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such filing. Item 9.01 — Financial Statements and Exhibits (d) Exhibits: Exhibit Description 99.1 Press release, dated October 28 , 2026, entitled "T-Mobile Delivers Strong Account and ARPA Growth, Translating into Industry-Leading Service Revenue , Profitability and EPS Growth " 99.2 Investor Factbook of T-Mobile US, Inc. Third Quarter 2026 Results 104 Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101) 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. T-MOBILE US, INC. October 28, 2026 /s/ Peter Osvaldik Peter Osvaldik Chief Financial Officer