Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Note 1 – Summary of Significant Accounting Policies Basis of Presentation The unaudited condensed consolidated financial statements of T-Mobile US, Inc. (“T-Mobile,” “we,” “our,” “us” or the “Company”) include all adjustments of a normal recurring nature necessary for the fair presentation of the results for the interim periods presented. The results for the interim periods are not necessarily indicative of those for the full year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024. The condensed consolidated financial statements include the balances and results of operations of T-Mobile and our consolidated subsidiaries. We consolidate majority-owned subsidiaries over which we exercise control, variable interest entities (“VIEs”) for which we are deemed to be the primary beneficiary and VIEs which cannot be deconsolidated, such as those related to our tower obligations as discussed in Note 9 - Tower Obligations. Intercompany transactions and balances have been eliminated in consolidation. Investments in entities that we do not control but have significant influence are accounted for under the equity method. We record our proportionate share of our equity method investees’ earnings within Other (expense) income, net on our Condensed Consolidated Statements of Comprehensive Income. The preparation of financial statements in conformity with United States (“U.S.”) generally accepted accounting principles (“GAAP”) requires our management to make estimates and assumptions that affect the financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and other assumptions that management believes are reasonable under the circumstances. Estimates are inherently subject to judgment and actual results could differ from those estimates. Accounting Pronouncements Not Yet Adopted Income Tax Disclosures In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” The standard enhances income tax disclosure requirements for all entities by requiring specified categories and greater disaggregation within the rate reconciliation table, disclosure of income taxes paid by jurisdiction, and providing clarification on uncertain tax positions and related financial statement impacts. The standard will be effective for us for our fiscal year 2025 annual financial statements with early adoption permitted. We plan to adopt the standard when it becomes effective for us beginning in our fiscal year 2025 annual financial statements, and we expect the adoption of the standard will impact certain of our income tax disclosures. Disaggregation of Income Statement Expenses In November 2024, the FASB issued ASU 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” In January 2025, the FASB issued ASU 2025-01, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date,” which clarifies the effective date of ASU 2024-03. The standard requires that public business entities disclose additional information about specific expense categories in the notes to financial statements for interim and annual reporting periods. The standard will become effective for us for our fiscal year 2027 annual financial statements and interim financial statements thereafter and may be applied prospectively to periods after the adoption date or retrospectively for all prior periods presented in the financial statements, with early adoption permitted. We plan to adopt the standard when it becomes effective for us beginning in our fiscal year 2027 annual financial statements, and we are currently evaluating the impact this guidance will have on the disclosures included in the Notes to the Consolidated Financial Statements.

The unaudited condensed consolidated financial statements of T-Mobile US, Inc. (“T-Mobile,” “we,” “our,” “us” or the “Company”) include all adjustments of a normal recurring nature necessary for the fair presentation of the results for the interim periods presented. The results for the interim periods are not necessarily indicative of those for the full year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2024.

The condensed consolidated financial statements include the balances and results of operations of T-Mobile and our consolidated subsidiaries. We consolidate majority-owned subsidiaries over which we exercise control, variable interest entities (“VIEs”) for which we are deemed to be the primary beneficiary and VIEs which cannot be deconsolidated, such as those related to our tower obligations as discussed in Note 9 - Tower Obligations. Intercompany transactions and balances have been eliminated in consolidation. Investments in entities that we do not control but have significant influence are accounted for under the equity method. We record our proportionate share of our equity method investees’ earnings within Other (expense) income, net on our Condensed Consolidated Statements of Comprehensive Income.

The preparation of financial statements in conformity with United States (“U.S.”) generally accepted accounting principles (“GAAP”) requires our management to make estimates and assumptions that affect the financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and other assumptions that management believes are reasonable under the circumstances. Estimates are inherently subject to judgment and actual results could differ from those estimates.

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” The standard enhances income tax disclosure requirements for all entities by requiring specified categories and greater disaggregation within the rate reconciliation table, disclosure of income taxes paid by jurisdiction, and providing clarification on uncertain tax positions and related financial statement impacts. The standard will be effective for us for our fiscal year 2025 annual financial statements with early adoption permitted. We plan to adopt the standard when it becomes effective for us beginning in our fiscal year 2025 annual financial statements, and we expect the adoption of the standard will impact certain of our income tax disclosures.

In November 2024, the FASB issued ASU 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” In January 2025, the FASB issued ASU 2025-01, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date,” which clarifies the effective date of ASU 2024-03. The standard requires that public business entities disclose additional information about specific expense categories in the notes to financial statements for interim and annual reporting periods. The standard will become effective for us for our fiscal year 2027 annual financial statements and interim financial statements thereafter and may be applied prospectively to periods after the adoption date or retrospectively for all prior periods presented in the financial statements, with early adoption permitted. We plan to adopt the standard when it becomes effective for us beginning in our fiscal year 2027 annual financial statements, and we are currently evaluating the impact this guidance will have on the disclosures included in the Notes to the Consolidated Financial Statements.