v3.25.4
Cover Page - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2025
Feb. 06, 2026
Jun. 30, 2025
Entity Listings [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 1-33409    
Entity Registrant Name T-MOBILE US, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 20-0836269    
Entity Address, Address Line One 12920 SE 38th Street    
Entity Address, City or Town Bellevue    
Entity Address, State or Province WA    
Entity Address, Postal Zip Code 98006-1350    
City Area Code (425)    
Local Phone Number 378-4000    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 112.4
Entity Common Stock, Shares Outstanding (in shares)   1,101,862,739  
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.
    
Entity Central Index Key 0001283699    
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Common Stock, par value $0.00001 per share      
Entity Listings [Line Items]      
Title of 12(b) Security Common Stock, par value $0.00001 per share    
Trading Symbol TMUS    
Security Exchange Name NASDAQ    
3.550% Senior Notes due 2029      
Entity Listings [Line Items]      
Title of 12(b) Security 3.550% Senior Notes due 2029    
Trading Symbol TMUS29    
Security Exchange Name NASDAQ    
3.700% Senior Notes due 2032      
Entity Listings [Line Items]      
Title of 12(b) Security 3.700% Senior Notes due 2032    
Trading Symbol TMUS32    
Security Exchange Name NASDAQ    
3.150% Senior Notes due 2032      
Entity Listings [Line Items]      
Title of 12(b) Security 3.150% Senior Notes due 2032    
Trading Symbol TMUS32A    
Security Exchange Name NASDAQ    
3.850% Senior Notes due 2036      
Entity Listings [Line Items]      
Title of 12(b) Security 3.850% Senior Notes due 2036    
Trading Symbol TMUS36    
Security Exchange Name NASDAQ    
3.500% Senior Notes due 2037      
Entity Listings [Line Items]      
Title of 12(b) Security 3.500% Senior Notes due 2037    
Trading Symbol TMUS37    
Security Exchange Name NASDAQ    
3.800% Senior Notes due 2045      
Entity Listings [Line Items]      
Title of 12(b) Security 3.800% Senior Notes due 2045    
Trading Symbol TMUS45    
Security Exchange Name NASDAQ    
6.250% Senior Notes due 2069      
Entity Listings [Line Items]      
Title of 12(b) Security 6.250% Senior Notes due 2069    
Trading Symbol TMUSL    
Security Exchange Name NASDAQ    
5.500% Senior Notes due March 2070      
Entity Listings [Line Items]      
Title of 12(b) Security 5.500% Senior Notes due March 2070    
Trading Symbol TMUSZ    
Security Exchange Name NASDAQ    
5.500% Senior Notes due June 2070      
Entity Listings [Line Items]      
Title of 12(b) Security 5.500% Senior Notes due June 2070    
Trading Symbol TMUSI    
Security Exchange Name NASDAQ