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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2025

or

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 1-33409

T-MOBILE US, INC.

(Exact name of registrant as specified in its charter)

12920 SE 38th Street

Bellevue, Washington

(Address of principal executive offices)

98006-1350

(Zip Code)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

As of June 30, 2025, the aggregate market value of the voting and non-voting common equity held by non-affiliates was $112.4 billion based on the closing sale price as reported on the NASDAQ Global Select Market. As of February 6, 2026, there were 1,101,862,739 shares of common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Part III of this Annual Report on Form 10-K will be incorporated by reference from certain portions of the definitive Proxy Statement for the Registrant’s 2026 Annual Meeting of Stockholders, which definitive Proxy Statement will be filed with the Securities and Exchange Commission pursuant to Regulation 14A or will be included in an amendment to this Report.

T-Mobile US, Inc.

Form 10-K

For the Year Ended December 31, 2025

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Cautionary Statement Regarding Forward-Looking Statements

This Annual Report on Form 10-K (“Form 10-K”) of T-Mobile US, Inc. (“T-Mobile,” “we,” “our,” “us” or the “Company”) includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including information concerning our future results of operations, are forward-looking statements. These forward-looking statements are generally identified by the words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “could” or similar expressions. Forward-looking statements are based on current expectations and assumptions, which are subject to risks and uncertainties that may cause actual results to differ materially from the forward-looking statements. The following important factors, along with the Risk Factors included in Part I, Item 1A of this Form 10-K, could affect future results and cause those results to differ materially from those expressed in the forward-looking statements:

• competition, industry consolidation and changes in the market for wireless communications services and other forms of connectivity;

• cyberattacks, disruptions, data loss or other security breaches;

• our inability to adopt and deploy network technologies in a timely and effective manner;

• our inability to effectively execute our digital transformation and drive customer and employee adoption of emerging technologies;

• our inability to retain or motivate key personnel, hire qualified personnel or maintain our corporate culture;

• system failures and business disruptions, allowing for unauthorized use of or interference with our network and other systems;

• the scarcity and cost of additional wireless spectrum, and regulations relating to spectrum use;

• the timing and effects of any pending and future acquisition, investment, joint venture, merger, or divestiture involving us, including our inability to obtain any required regulatory approval necessary to consummate any such transactions or to achieve the expected benefits of such transactions;

• adverse economic, political or market conditions in the U.S. and international markets, including changes resulting from increases in inflation or interest rates, tariffs and trade restrictions, supply chain disruptions, fluctuations in global currencies, immigration policies, and impacts of geopolitical instability, such as the Ukraine-Russia, Iran-Israel and Israel-Hamas wars and further escalations thereof;

• operational delays, higher procurement and operational costs, and increased regulatory and compliance complexities, for example, as a result of changes to trade policies, including higher tariffs, restrictions and other economic disincentives to trade;

• our inability to successfully deliver new products and services;

• any failure or inability of our third parties (including key suppliers) to provide products or services for the operation of our business;

• sociopolitical volatility and polarization and risks related to environmental, social and governance matters;

• our substantial level of indebtedness and our inability to service our debt obligations in accordance with their terms;

• changes in the credit market conditions, credit rating downgrades or an inability to access debt markets;

• our inability to maintain effective internal control over financial reporting;

• compliance with the current regulatory framework, including our national security obligations, and any changes in regulations or in the regulatory framework under which we operate;

• laws and regulations relating to the handling of privacy, data protection and artificial intelligence (“AI”);

• unfavorable outcomes of and increased costs from existing or future regulatory or legal proceedings;

• difficulties in protecting our intellectual property rights or if we infringe on the intellectual property rights of others;

• our offering of regulated financial services products and exposure to a wide variety of state and federal regulations;

• new or amended tax laws or regulations or administrative interpretations and judicial decisions affecting the scope or application of tax laws or regulations;

• our wireless licenses, including those controlled through leasing agreements, are subject to renewal and may be revoked;

• our exclusive forum provision as provided in our Certificate of Incorporation;

• interests of Deutsche Telekom AG (“DT”), our controlling stockholder, which may differ from the interests of other stockholders;

• our current and future stockholder return programs may not be fully utilized, and our share repurchases and dividend payments pursuant thereto may fail to have the desired impact on stockholder value; and

• future sales of our common stock by DT and our inability to attract additional equity financing outside the United States due to foreign ownership limitations by the Federal Communications Commission (“FCC”).

Given these risks and uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. We undertake no obligation to revise or publicly release the results of any revision to these forward-looking statements, except as required by law.

In addition, historical, current, and forward-looking environmental sustainability related statements may be based on standards for measuring progress that are still developing and internal controls and processes that continue to evolve. These initiatives are subject to additional risks and uncertainties, including regarding the evolving nature of data availability, quality, and assessment; related methodological concerns; our ability to implement various initiatives under expected timeframes, cost, and complexity; our dependency on third parties to provide certain information and to comply with applicable laws and policies; and other unforeseen events or conditions. For example, we note that standards and expectations regarding greenhouse gas (“GHG”) accounting and the processes for measuring and counting GHG emissions and GHG emission reductions are evolving, and it is possible that our approaches both to measuring our emissions and to reducing emissions and measuring those reductions may be, either currently by some stakeholders or at some point in the future, considered inconsistent with common or best practices with respect to measuring and accounting for such matters, and reducing overall emissions. These factors, as well as others, may cause results to differ materially and adversely from those expressed in any of our forward-looking statements. Additionally, we may provide information that is not necessarily material for SEC reporting purposes but that is informed by various other standards and frameworks (including standards for the measurement of underlying data), internal controls, and assumptions or third-party information that are still evolving and subject to change. Our disclosures based on any standards may change due to revisions in framework requirements, availability of information, changes in our business or applicable governmental policies, or other factors, some of which may be beyond our control.

Investors and others should note that we announce material information to our investors using our investor relations website (https://investor.t-mobile.com), newsroom website (https://t-mobile.com/news), press releases, SEC filings and public conference calls and webcasts. We intend to also use certain social media accounts as a means of disclosing information about us and our services and for complying with our disclosure obligations under Regulation FD (the @TMobileIR X account (https://x.com/TMobileIR), the @SriniGopalan X account (https://x.com/SriniGopalan) and our CEO’s LinkedIn account (https://www.linkedin.com/in/srini-gopalan/), both of which Mr. Gopalan also uses as a means for personal communications and observations, and the @TMobileCFO X account (https://x.com/tmobilecfo) and our Chief Financial Officer’s LinkedIn account (https://www.linkedin.com/in/peter-osvaldik-3887394), both of which Mr. Osvaldik also uses as a means for personal communication and observations). The information we post through these social media channels may be deemed material. Accordingly, investors should monitor these social media channels in addition to following our press releases, SEC filings and public conference calls and webcasts. The social media channels that we intend to use as a means of disclosing the information described above may be updated from time to time as listed on our investor relations website.

PART I.