T-Mobile US (TMUS) 10-Q 5 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	1-33409
Entity Registrant Name	T-MOBILE US, INC.
Entity Central Index Key	0001283699
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
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
Title of 12(b) Security	Common Stock, par value $0.00001 per share
Trading Symbol	TMUS
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,241,186,776

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 6,571	$ 1,528
Accounts receivable, net of allowance for credit losses of $208 and $61	4,313	1,888
Equipment installment plan receivables, net of allowance for credit losses and imputed discount of $386 and $333	3,083	2,600
Accounts receivable from affiliates	19	20
Inventory	1,931	964
Prepaid expenses	659	333
Other current assets	2,889	1,972
Total current assets	19,465	9,305
Property and equipment, net	38,567	21,984
Operating lease right-of-use assets	27,999	10,933
Financing lease right-of-use assets	3,038	2,715
Goodwill	10,906	1,930
Spectrum licenses	82,891	36,465
Other intangible assets, net	5,660	115
Equipment installment plan receivables due after one year, net of allowance for credit losses and imputed discount of $83 and $66	1,398	1,583
Other assets	2,519	1,891
Total assets	192,443	86,921
Current liabilities
Accounts payable and accrued liabilities	8,389	6,746
Payables to affiliates	135	187
Short-term debt	3,713	25
Deferred revenue	1,078	631
Short-term operating lease liabilities	3,658	2,287
Short-term financing lease liabilities	1,050	957
Other current liabilities	1,817	1,673
Total current liabilities	19,840	12,506
Long-term debt	58,345	10,958
Long-term debt to affiliates	4,711	13,986
Tower obligations	3,079	2,236
Deferred tax liabilities	10,373	5,607
Operating lease liabilities	26,658	10,539
Financing lease liabilities	1,373	1,346
Other long-term liabilities	3,577	954
Total long-term liabilities	108,116	45,626
Commitments and contingencies (Note 17)
Stockholders' equity
Common Stock, par value $0.00001 per share, 2,000,000,000 shares authorized; 1,242,003,310 and 858,418,615 shares issued, 1,240,458,618 and 856,905,400 shares outstanding	0	0
Additional paid-in capital	72,705	38,498
Treasury stock, at cost, 1,544,692 and 1,513,215 shares issued	(11)	(8)
Accumulated other comprehensive loss	(1,621)	(868)
Accumulated deficit	(6,586)	(8,833)
Total stockholders' equity	64,487	28,789
Total liabilities and stockholders' equity	$ 192,443	$ 86,921

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for credit losses	$ 208	$ 61
Allowance for credit losses and imputed discount	450	333
Allowance for credit losses and imputed discount	$ 87	$ 66
Common stock, par value (in USD per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	1,242,003,310	858,418,615
Common stock, shares outstanding (in shares)	1,240,458,618	856,905,400
Treasury stock, at cost (in shares)	1,544,692	1,513,215

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues
Revenues	$ 19,272	$ 11,061	$ 48,056	$ 33,120
Operating expenses
Selling, general and administrative	4,876	3,498	14,168	10,483
Impairment expense	0	0	418	0
Depreciation and amortization	4,150	1,655	9,932	4,840
Total operating expenses	16,707	9,590	43,132	28,632
Operating income	2,565	1,471	4,924	4,488
Other income (expense)
Interest expense	(765)	(184)	(1,726)	(545)
Interest expense to affiliates	(44)	(100)	(206)	(310)
Interest income	3	5	21	17
Other (expense) income, net	(99)	3	(304)	(12)
Total other expense, net	(905)	(276)	(2,215)	(850)
Income from continuing operations before income taxes	1,660	1,195	2,709	3,638
Income tax expense	(407)	(325)	(715)	(921)
Income from continuing operations	1,253	870	1,994	2,717
Income from discontinued operations, net of tax	0	0	320	0
Net income	1,253	870	2,314	2,717
Net income	1,253	870	2,314	2,717
Other comprehensive loss, net of tax
Unrealized gain (loss) on cash flow hedges, net of tax effect of $12, $(88) , $(261) and $(256)	33	(257)	(757)	(738)
Unrealized gain on foreign currency translation adjustment, net of tax effect of $1, $0, $1, and $0	4	0	4	0
Other comprehensive income (loss)	37	(257)	(753)	(738)
Total comprehensive income	$ 1,290	$ 613	$ 1,561	$ 1,979
Earnings Per Share, Basic [Abstract]
Continuing operations (in USD per share)	$ 1.01	$ 1.02	$ 1.79	$ 3.18
Discontinued operations (in USD per share)	0	0	0.29	0
Basic (in USD per share)	1.01	1.02	2.08	3.18
Earnings Per Share, Diluted [Abstract]
Continuing operations (in USD per share)	1	1.01	1.78	3.15
Discontinued operations (in USD per share)	0	0	0.28	0
Diluted (in USD per share)	$ 1	$ 1.01	$ 2.06	$ 3.15
Weighted average shares outstanding
Basic (in shares)	1,238,450,665	854,578,241	1,111,511,964	853,391,370
Diluted (in shares)	1,249,798,740	862,690,751	1,122,040,528	862,854,654
Postpaid revenues
Revenues
Revenues	$ 10,209	$ 5,746	$ 26,055	$ 16,852
Prepaid revenues
Revenues
Revenues	2,383	2,385	7,067	7,150
Wholesale revenues
Revenues
Revenues	930	321	1,663	938
Roaming and other service revenues
Revenues
Revenues	617	261	1,430	710
Service
Revenues
Revenues	14,139	8,713	36,215	25,650
Operating expenses
Cost of services and equipment sales	3,314	1,733	8,051	4,928
Equipment
Revenues
Revenues	4,953	2,186	11,339	6,965
Operating expenses
Cost of services and equipment sales	4,367	2,704	10,563	8,381
Other revenues
Revenues
Revenues	$ 180	$ 162	$ 502	$ 505

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Cash flow hedges, tax effect	$ 12	$ (88)	$ (261)	$ (256)
Foreign currency translation adjustment, tax effect	$ 1	$ 0	$ 1	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating activities
Net income	$ 1,253	$ 870	$ 2,314	$ 2,717
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	4,150	1,655	9,932	4,840
Stock-based compensation expense	161	126	558	366
Deferred income tax expense	335	294	743	849
Bad debt expense	143	74	489	218
(Gains) losses from sales of receivables	(18)	28	37	91
Losses on redemption of debt	108	0	271	19
Impairment expense	0	0	418	0
Changes in operating assets and liabilities
Accounts receivable	(1,538)	(745)	(2,784)	(2,693)
Equipment installment plan receivables	(306)	(78)	(110)	(478)
Inventories	(549)	(36)	(1,613)	(139)
Operating lease right-of-use assets	1,062	491	2,526	1,395
Other current and long-term assets	(8)	(118)	(106)	(288)
Accounts payable and accrued liabilities	(964)	(395)	(2,630)	(339)
Short and long-term operating lease liabilities	(1,145)	(549)	(2,947)	(1,592)
Other current and long-term liabilities	(51)	42	(2,162)	136
Other, net	139	89	230	185
Net cash provided by operating activities	2,772	1,748	5,166	5,287
Investing activities
Purchases of property and equipment, including capitalized interest of $108, $118, $339 and $361	(3,217)	(1,514)	(7,227)	(5,234)
Refunds (purchases) of spectrum licenses and other intangible assets, including deposits	17
Refunds (purchases) of spectrum licenses and other intangible assets, including deposits		(13)	(827)	(863)
Proceeds related to beneficial interests in securitization transactions	855	900	2,325	2,896
Net cash related to derivative contracts under collateral exchange arrangements	0	0	632	0
Acquisition of companies, net of cash and restricted cash acquired	0	(31)	(5,000)	(31)
Proceeds from the divestiture of prepaid business	1,238	0	1,238	0
Other, net	(25)	1	(209)	(6)
Net cash used in investing activities	(1,132)	(657)	(9,068)	(3,238)
Financing activities
Proceeds from issuance of long-term debt	0	0	26,694	0
Payments of consent fees related to long-term debt	0	0	(109)	0
Proceeds from borrowing on revolving credit facility	0	575	0	2,340
Repayments of revolving credit facility	0	(575)	0	(2,340)
Repayments of financing lease obligations	(246)	(235)	(764)	(550)
Repayments of short-term debt for purchases of inventory, property and equipment and other financial liabilities	(231)	(300)	(407)	(300)
Repayments of long-term debt	(5,678)	0	(16,207)	(600)
Issuance of common stock	2,550	0	19,840	0
Repurchases of common stock	(2,546)	0	(19,536)	0
Proceeds from issuance of short-term debt	0	0	18,743	0
Repayments of short-term debt	0	0	(18,929)	0
Tax withholdings on share-based awards	(72)	(4)	(351)	(108)
Cash payments for debt prepayment or debt extinguishment costs	(58)	0	(82)	(28)
Other, net	137	(4)	139	(13)
Net cash (used in) provided by financing activities	(6,144)	(543)	9,031	(1,599)
Change in cash and cash equivalents, including restricted cash	(4,504)	548	5,129	450
Cash and cash equivalents, including restricted cash
Beginning of period	11,161	1,105	1,528	1,203
End of period	$ 6,657	$ 1,653	$ 6,657	$ 1,653

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Cash Flows [Abstract]
Capitalized interest	$ 108	$ 118	$ 339	$ 361

Condensed Consolidated Statem_5

Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Millions		Total	Common Stock Outstanding	Treasury Shares at Cost	Par Value and Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance, beginning of period at Dec. 31, 2018		$ 24,718		$ (6)	$ 38,010	$ (332)	$ (12,954)
Common stock outstanding, beginning balance (in shares) at Dec. 31, 2018			850,180,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		2,717					2,717
Other comprehensive (loss) income		(738)				(738)
Stock-based compensation		404			404
Exercise of stock options		1			1
Exercise of stock options (in shares)			70,754
Stock issued for employee stock purchase plan		124			124
Stock issued for employee stock purchase plan (in shares)			2,091,650
Issuance of vested restricted stock units (in shares)			4,729,270
Issuance of restricted stock awards (in shares)			(20,769)
Shares withheld related to net share settlement of stock awards and stock options		(108)			(108)
Shares withheld related to net share settlement of stock awards and stock options (in shares)			(1,474,011)
Transfer RSU from NQDC plan				(2)	2
Transfer RSU to NQDC plan (in shares)			(19,540)
Prior year Retained Earnings		653					653
Balance, end of period at Sep. 30, 2019		27,771		(8)	38,433	(1,070)	(9,584)
Common stock outstanding, ending balance (in shares) at Sep. 30, 2019			855,557,671
Balance, beginning of period at Jun. 30, 2019		26,967		(8)	38,242	(813)	(10,454)
Common stock outstanding, beginning balance (in shares) at Jun. 30, 2019			854,452,642
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		870					870
Other comprehensive (loss) income		(257)				(257)
Stock-based compensation		140			140
Exercise of stock options (in shares)			19,619
Stock issued for employee stock purchase plan		55			55
Stock issued for employee stock purchase plan (in shares)			955,849
Issuance of vested restricted stock units (in shares)			179,155
Shares withheld related to net share settlement of stock awards and stock options		$ (4)			(4)
Shares withheld related to net share settlement of stock awards and stock options (in shares)			(53,349)
Distribution from NQDC plan (in shares)		3,755
Balance, end of period at Sep. 30, 2019		$ 27,771		(8)	38,433	(1,070)	(9,584)
Common stock outstanding, ending balance (in shares) at Sep. 30, 2019			855,557,671
Balance, beginning of period at Dec. 31, 2019		$ 28,789		(8)	38,498	(868)	(8,833)
Common stock outstanding, beginning balance (in shares) at Dec. 31, 2019		856,905,400	856,905,400
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		$ 2,314					2,314
Other comprehensive (loss) income		(753)				(753)
Executive put option		1			1
Executive put option (in shares)			(342,000)
Stock-based compensation		601			601
Exercise of stock options		42			42
Exercise of stock options (in shares)			794,853
Stock issued for employee stock purchase plan		148			148
Stock issued for employee stock purchase plan (in shares)			2,144,036
Issuance of vested restricted stock units (in shares)			11,295,402
Shares withheld related to net share settlement of stock awards and stock options		(351)			(351)
Shares withheld related to net share settlement of stock awards and stock options (in shares)			(3,703,906)
Transfer RSU from NQDC plan				(3)	3
Transfer RSU to NQDC plan (in shares)			(31,477)
Shares issued in secondary offering	[1]	19,766			19,766
Shares issued in secondary offering (in shares)	[1]		198,314,426
Shares repurchased from SoftBank	[2]	$ (19,536)			(19,536)
Shares repurchased from SoftBank (in shares)	[2]	(198,314,426)
Merger consideration		$ 33,533			33,533
Purchase price consideration (in shares)			373,396,310
Prior year Retained Earnings		(67)					(67)
Balance, end of period at Sep. 30, 2020		$ 64,487		(11)	72,705	(1,621)	(6,586)
Common stock outstanding, ending balance (in shares) at Sep. 30, 2020		1,240,458,618	1,240,458,618
Balance, beginning of period at Jun. 30, 2020		$ 62,996		(12)	72,505	(1,658)	(7,839)
Common stock outstanding, beginning balance (in shares) at Jun. 30, 2020			1,237,338,994
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		1,253					1,253
Other comprehensive (loss) income		37				37
Stock-based compensation		177			177
Exercise of stock options		27			27
Exercise of stock options (in shares)			483,266
Stock issued for employee stock purchase plan		65			65
Stock issued for employee stock purchase plan (in shares)			897,732
Issuance of vested restricted stock units (in shares)			2,383,098
Shares withheld related to net share settlement of stock awards and stock options		(72)			(72)
Shares withheld related to net share settlement of stock awards and stock options (in shares)			(648,872)
Distribution from NQDC plan				1	(1)
Distribution from NQDC plan (in shares)			4,400
Shares issued in secondary offering	[1]	2,550			2,550
Shares issued in secondary offering (in shares)	[1]		24,750,000
Shares repurchased from SoftBank		$ (2,546)			(2,546)
Shares repurchased from SoftBank (in shares)		(24,750,000)
Balance, end of period at Sep. 30, 2020		$ 64,487		$ (11)	$ 72,705	$ (1,621)	$ (6,586)
Common stock outstanding, ending balance (in shares) at Sep. 30, 2020		1,240,458,618	1,240,458,618
[1]	Shares issued includes 5.0 million shares purchased by Marcelo Claure.
[2]	In connection with the SoftBank Monetization (as defined below) we received a payment of $304 million from SoftBank (as defined below). This amount, net of tax, was treated as a reduction of the purchase price of the shares acquired from SoftBank and was recorded as Additional paid-in capital.

Condensed Consolidated Statem_6

Condensed Consolidated Statement of Stockholders' Equity (Parenthetical) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)shares
Marcelo Claure
Shares sold (in shares) | shares	5
Par Value and Additional Paid-in Capital
Payment received to facilitate SoftBank Monetization | $	$ 304

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
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, 2019. On April 29, 2018, we entered into a Business Combination Agreement (the “Business Combination Agreement”) to merge with Sprint Corporation (“Sprint”) in an all-stock transaction at a fixed exchange ratio of 0.10256 shares of T-Mobile common stock for each share of Sprint common stock, or 9.75 shares of Sprint common stock for each share of T-Mobile common stock (the “Merger”). On April 1, 2020, we completed the Merger and acquired Sprint (see Note 2 - Business Combination ). On July 26, 2019, pursuant to the requirement as set forth in the U.S. Department of Justice’s (the “DOJ”) complaint and proposed final judgement (the “Consent Decree”), T-Mobile entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Sprint and DISH Network Corporation (“DISH”). Pursuant to the Asset Purchase Agreement and upon the terms and subject to the conditions thereof, on July 1, 2020, DISH acquired the prepaid wireless business operated under the Boost Mobile and Sprint prepaid brands (excluding the Assurance brand Lifeline customers and the prepaid wireless customers of Shenandoah Telecommunications Company and Swiftel Communications, Inc.), including customer accounts, inventory, contracts, intellectual property and certain other specified assets (the “Prepaid Business”) and assumed certain related liabilities (the “Prepaid Transaction”). Upon closing of the Prepaid Transaction, we received $1.4 billion from DISH, subject to a working capital adjustment. The revenues and expenses of the Prepaid Business are presented as discontinued operations for the nine months ended September 30, 2020. 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, as well as variable interest entities (“VIEs”) where we are deemed to be the primary beneficiary and VIEs which cannot be deconsolidated, such as those related to our obligations to pay for the management and operation of certain of our wireless communications tower sites. Intercompany transactions and balances have been eliminated in consolidation. 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 which affect the financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and other assumptions which our management believes are reasonable under the circumstances, including but not limited to the valuation of assets acquired and liabilities assumed through the Merger with Sprint and the potential impacts arising from the COVID-19 pandemic. These estimates are inherently subject to judgment and actual results could differ from those estimates. Significant Accounting Policies Upon the close of our Merger with Sprint, we have adopted or applied the significant accounting policies described below to the applicable transactions and activities of the consolidated company. Spectrum Leases Through the Merger, the Company acquired lease agreements (the “Agreements”) with various educational and non-profit institutions that provide us with the right to use Federal Communications Commission (“FCC”) spectrum licenses (Educational Broadband Services or “EBS spectrum”) in the 2.5 GHz band. In addition to the Agreements with educational institutions and private owners who hold the license, the Company also acquired direct ownership of spectrum licenses previously acquired by Sprint through government auctions or other acquisitions. The Agreements with educational and certain non-profit institutions are typically for five Leased FCC spectrum licenses are recorded as executory contracts whereby, as a result of business combination accounting, an intangible asset or liability is recorded reflecting the extent to which contractual terms are favorable or unfavorable to current market rates. These intangible assets or liabilities are amortized over the estimated remaining useful life of the lease agreements. Contractual lease payments are recognized on a straight-line basis over the remaining term of the arrangement, including renewals, and are presented in Costs of services within our Condensed Consolidated Statements of Comprehensive Income. Owned FCC spectrum licenses are classified as indefinite-lived intangible assets which are assessed for impairment annually, or more frequently, if facts and circumstances warrant. The Agreements enhance the value of the Company’s owned spectrum licenses as the collective value is higher than the value of individual bands of spectrum within a specific geography. This value is derived from the ability to provide wireless service to customers across large geographic areas and maintain the same or similar wireless connectivity quality. This enhanced value from combining owned and leased spectrum licenses to create contiguous spectrum is referred to as an aggregation premium. We recognized the aggregation premium as part of the FCC spectrum licenses indefinite-lived intangible assets. Brightstar Distribution We have arrangements with Brightstar US, Inc. (“Brightstar”), a subsidiary of SoftBank, whereby Brightstar provides supply chain and inventory management services to us in our indirect channels. T-Mobile may sell devices through Brightstar to T-Mobile indirect dealers who then sell the device to the end customer (i.e., the service subscriber). The supply chain and inventory management arrangement includes, among other things, that Brightstar may purchase inventory from the original equipment manufacturers (“OEM”) to sell directly to our indirect dealers. As compensation for these services, we remit per unit fees to Brightstar for each device sold to these indirect dealers. Devices sold from T-Mobile to Brightstar do not meet the criteria for a sale. Devices transferred from T-Mobile to Brightstar remain in inventory until control is transferred upon the sale of the device to the end customers, and in some circumstances to the indirect dealer. For service subscribers who choose to lease a device previously sold to the indirect dealer, T-Mobile will repurchase the device from the indirect dealer and originate a lease directly with the end customer. Repurchase activity from the indirect dealer is estimated and treated as a right of return, reducing equipment revenue at the time of sale to the indirect dealer. Upon lease to the end customer, T-Mobile recognizes lease revenue over the associated lease term within Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income. Device Leases Through the Merger, we acquired device lease contracts in which Sprint is the lessor (the “Sprint Flex Lease Program”), substantially all of which are classified as operating leases, as well as the associated fixed assets (i.e., the leased devices). These leased devices were recorded as fixed assets at their acquisition date fair value and presented within Property and equipment, net on our Condensed Consolidated Balance Sheets. Our leasing programs include JUMP! On Demand and the Sprint Flex Lease Program acquired through the Merger. We depreciate leased devices on a group basis using the straight-line method over the estimated useful life of the device. The estimated useful life reflects the period for which we estimate the group of leased devices will provide utility to us, which may be longer than the initial lease term based on customer options in the Sprint Flex Lease program to renew the lease on a month-to-month basis after the initial lease term concludes. In determining the estimated useful life, we consider the lease term (e.g., 18 months and month-to-month renewal options for the Sprint Flex Lease Program), trade-in activity and write-offs for lost and stolen devices. Lost and stolen devices are incorporated into the estimates of depreciation expense and recognized as an adjustment to accumulated depreciation when the loss event occurs. Our policy of using the group method of depreciation has been applied to acquired leased devices as well as leases originated subsequent to the Merger close. Acquired leased devices are grouped based on the age of the device. Revenues associated with the leased wireless devices, net of lease incentives, are generally recognized straight-line over the lease term. Upon device upgrade or at lease end, customers in the JUMP! on Demand lease program must return or purchase their device, and customers in the Sprint Flex Lease Program have the option to return or purchase their device or to renew their lease on a month-to-month basis at the end of the lease term. Returned devices are transferred from Property and equipment, net to Inventory on our Condensed Consolidated Balance Sheets and are valued at the lower of cost or net realizable value, with any write-down recognized as Cost of equipment sales in our Condensed Consolidated Statements of Comprehensive Income. Cost to Acquire a Contract We capitalize postpaid sales commissions for service activation as costs to acquire a contract and amortize them over the estimated period of benefit, currently 24 months. Prepaid commissions are expensed as incurred as their estimated period of benefit does not extend beyond 12 months. Commissions paid upon device upgrade are not capitalized if a customer contract is less than one year. Commissions paid when the customer has a lease are treated as initial direct costs and recognized over the lease term. Our policies for the capitalization and amortization of costs to acquire a contract are applied to the Sprint, Boost (up to the sale of the Boost prepaid business to Dish on July 1, 2020) and Assurance Wireless brands subsequent to the Merger close. Device Purchases Cash Flow Presentation We classify all device purchases, whether acquired for sale or lease, as operating cash outflows as our predominant strategy is to sell devices to customers rather than lease them. See Note 19 – Additional Financial Information for disclosures of Leased devices transferred from inventory to property and equipment and Returned leased devices transferred from property and equipment to inventory. Imputed Interest on EIP Receivables We record the effects of financing on all equipment installment plan (“EIP”) loans regardless of whether or not the financing is considered to be significant. The imputation of interest results in a discount of the EIP receivable, thereby adjusting the transaction price of the contract with the customer, which is then allocated to the performance obligations of the arrangement. For indirect channel loans to the end service customer in which the sale of the device was to the dealer (sell-in basis), the effect of imputing interest is recognized as a reduction to service revenue over the service contract period, the only performance obligation with the service customer as the device sale was recognized when transferred to the dealer. Our policies for imputed interest on EIP receivables are applied to loans originated for Sprint and Boost (up to the sale of the Boost prepaid business to DISH on July 1, 2020) customers subsequent to Merger close. Cell Tower Lease-Out and Leaseback Arrangement Prior to the Merger, Sprint entered into a lease-out and leaseback agreement with Global Signal, Inc. a third party that was subsequently acquired by Crown Castle International Corp. (“CCI”). CCI was granted exclusive rights to lease 6,600 communications towers (lease-out) for 32 years, which were originally constructed by Sprint on land that Sprint leased from individual landowners. Sprint received upfront proceeds in 2005 of $1.2 billion and obtained the right to use a portion of the space on the towers with a stipulated monthly payment (leaseback), generally with a ten-year initial term with five-year renewal options. The arrangement is accounted for as a financing, with the cell towers owned by Sprint included in Property and equipment and a financing obligation for the amounts contractually due to CCI included in Tower obligations in our Condensed Consolidated Balance Sheets. The tower assets are depreciated to their estimated residual value and payments to CCI are recognized as interest expense and a reduction to the financing obligation. See Note 9 – Tower Obligations for further information on this arrangement. Wireline revenue Performance obligations related to our Wireline customers involve the provision of services to corporate customers. Wireline service performance obligations are typically satisfied over a period between 24 and 36 months. Amounts due for services are invoiced and collected periodically over the relevant service period. Wireline contracts are not subject to significant amounts of variable consideration, other than charges intended to partially recover taxes imposed on the Company, including fees related to the Universal Service Fund. Such fees are based on the customer's monthly usage and are therefore included in the corresponding distinct months of Wireline services. Our Wireline contracts do provide the customer with monthly options to purchase goods or services at prices commensurate with the standalone selling prices for those goods or services, as determined at contract inception. Wireline revenues are included within Roaming and other service revenues in our Condensed Consolidated Statements of Comprehensive Income. Sprint Retirement Pension Plan Through the Merger, we acquired the assets and assumed the liabilities associated with the Sprint Retirement Pension Plan (the “Pension Plan”), which is a defined benefit pension plan providing postretirement benefits to certain employees. As of December 31, 2005, the Pension Plan was amended to freeze benefit plan accruals for participants. The investments in the Pension Plan are measured at fair value on a recurring basis each quarter using quoted market prices or the net asset value per share as a practical expedient. The projected benefit obligations associated with the Pension Plan are determined based on actuarial models utilizing mortality tables and discount rates applied to the expected benefit term. Restricted Cash Certain provisions of our debt agreements require us to maintain specified cash collateral balances. Amounts associated with these balances are considered to be restricted cash and are included within Other assets in our Condensed Consolidated Balance Sheets. Advertising and Search Revenues Effective April 1, 2020, certain of our advertising and search revenues are now presented within Roaming and other service revenues, resulting in a reclassification of $130 million and $364 million for the three and nine months ended September 30, 2019, respectively. These revenues were previously presented within Other revenues in our Condensed Consolidated Statements of Comprehensive Income. Prior periods have been reclassified to conform to current period presentation. Accounting Pronouncements Adopted During the Current Year Receivables and Expected Credit Losses In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” and has since modified the standard with several ASUs (collectively, the “new credit loss standard”). The new credit loss standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions and reasonable and supportable forecasts that affect the collectibility of the reported amount. The new credit loss standard became effective for us, and we adopted the standard, on January 1, 2020. The new credit loss standard required a cumulative-effect adjustment to Accumulated deficit at the date of initial application, and as a result, we did not restate prior periods presented in the condensed consolidated financial statements. Under the new credit loss standard, we recognize lifetime expected credit losses at the inception of our credit risk exposures whereas we previously recognized credit losses only when it was probable that they had been incurred. We also recognize expected credit losses on our EIP receivables, which are inclusive of all installment receivables acquired in the Merger or issued thereafter, separately from, and in addition to, any unamortized discount on those receivables. Prior to the adoption of the new credit loss standard, we had offset our estimate of probable losses on our EIP receivables by the amount of the related unamortized discounts on those receivables. We have developed an expected credit loss model incorporating forward-looking loss indicators. The cumulative effect of initially applying the new credit loss standard on our receivables portfolio on January 1, 2020 was an increase to our allowance for credit losses of $91 million, a decrease to our net deferred tax liabilities of $24 million and an increase to our Accumulated deficit of $67 million. For EIP receivables acquired in the Merger, we also recognize expected credit losses separately from, and in addition to, the acquisition date fair value of the acquired EIP receivables. Accounts Receivable Portfolio Segment Accounts receivable consists primarily of amounts currently due from customers (e.g., for wireless services and monthly device lease payments), handset insurance administrators, wholesale partners, other carriers and third-party retail channels. Accounts receivable are presented in our Condensed Consolidated Balance Sheets at the amortized cost basis (i.e., the receivables’ outstanding principal balance adjusted for any write-offs), net of the allowance for expected credit losses. We have an arrangement to sell certain of our customer service accounts receivable on a revolving basis, which are treated as sales of financial assets. Equipment Installment Plan Receivables Portfolio Segment We offer certain retail customers the option to pay for their devices and other purchases in installments, generally over a period of 24 months using an EIP. EIP receivables are presented in our Condensed Consolidated Balance Sheets at the amortized cost basis (i.e., the receivables’ unpaid principal balance adjusted for any write-offs and unamortized discounts), net of the allowance for expected credit losses. At the time of an installment sale, we impute a discount for interest if the term exceeds 12 months as there is no stated rate of interest on the receivables. The receivables are recorded at their present value, which is determined by discounting expected future cash payments at the imputed interest rate. This adjustment results in a discount which is allocated to the performance obligations of the arrangement and recorded as a reduction in transaction price in Total service revenues and Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income. The imputed discount rate is the current market interest rate and is predominately comprised of the estimated credit risk underlying the EIP receivable, reflecting the estimated credit worthiness of the customer. The imputed discount on receivables is amortized over the financed installment term using the effective interest method and recognized as Other revenues in our Condensed Consolidated Statements of Comprehensive Income. At the time that we originate EIP loans to customers, we recognize an allowance for credit losses that we expect to incur over the lifetime of such assets. This allowance represents the portion of the amortized cost basis of EIP receivables that we do not expect to collect. The current portion of the EIP receivables is included in Equipment installment plan receivables, net and the long-term portion of the EIP receivables is included in Equipment installment plan receivables due after one year, net in our Condensed Consolidated Balance Sheets. We have an arrangement to sell certain EIP receivables on a revolving basis, which are treated as sales of financial assets. Allowance for Credit Losses We maintain an allowance for expected credit losses and determine its appropriateness through an established process that assesses the lifetime credit losses that we expect to incur related to our receivable portfolio. Each period, management assesses the appropriateness of the level of allowance for credit losses by considering credit risk inherent within the portfolio of receivables, as of period end. We develop and document our allowance methodology for each of our accounts receivable and EIP receivable portfolio segments. While we attribute portions of the allowance to our respective accounts receivable and EIP portfolio segments, the entire allowance is available to absorb expected credit losses related to the total receivable portfolio. Determining the appropriate level of allowance for credit losses requires significant judgment. Our process involves procedures to appropriately consider the unique risk characteristics of our accounts receivable and EIP receivable portfolio segments. For each portfolio segment, losses are estimated collectively for groups of receivables with similar characteristics. Our allowance levels are influenced by receivable volumes, receivable delinquency status, historical loss experience and other conditions influencing loss expectations, such as changes in credit and collections policies and forecasts of macro-economic conditions. Total imputed discount and allowances, which includes all accounts receivable and EIP receivables acquired in the Merger or issued thereafter, were approximately 7.8% and 7.0% of the total amount of gross accounts receivable, including EIP receivables, at September 30, 2020 and December 31, 2019, respectively. We consider a receivable past due when a customer has not paid us by the contractually specified payment due date. Account balances are written off against the allowance for credit losses if collection efforts are unsuccessful and the receivable balance is deemed uncollectible, based on factors such as customer credit ratings as well as the length of time the amounts are past due. If there is a deterioration of our customers’ financial condition or if future actual default rates on receivables in general differ from those currently anticipated, we will adjust our allowance for credit losses accordingly, which may materially affect our financial results in the period the adjustments are made. Cloud Computing Arrangements In August 2018, the FASB issued ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Topic 350): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” The standard aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The standard also requires the presentation of the amortization of the capitalized implementation costs in the same line item in the Condensed Consolidated Statements of Comprehensive Income as the fees associated with the hosting arrangement. The standard became effective for us, and we adopted the standard, on January 1, 2020. We adopted the standard on a prospective basis applying it to implementation costs incurred subsequent to January 1, 2020 and as a result did not restate the prior periods presented in the condensed consolidated financial statements. The adoption of the standard did not have a material impact on our condensed consolidated financial statements for the nine months ended September 30, 2020. Income Taxes In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” The standard removes certain exceptions to the general principles in Topic 740. We early adopted the standard on January 1, 2020 and have applied the standard retrospectively to all periods presented. The adoption of this standard did not have a material impact on our condensed consolidated financial statements for the nine months ended September 30, 2020. Guarantor Financial Information On March 2, 2020, the Securities and Exchange Commission (the “SEC”) adopted amendments to the financial disclosure requirements for guarantors and issuers of guaranteed securities, as well as for affiliates whose securities collateralize a registrant’s securities. The amendments revise Rules 3-10 and 3-16 of Regulation S-X, and relocate part of Rule 3-10 and all of Rule 3-16 to the new Article 13 in Regulation S-X, which is comprised of new Rules 13-01 and 13-02. We early adopted the requirements of the amendments on January 1, 2020, which included replacing guarantor condensed consolidating financial information with summarized financial information for the consolidated obligor group (Parent, Issuer, and Guarantor Subsidiaries) as well as no longer requiring guarantor cash flow information, financial information for non-guarantor subsidiaries, and a reconciliation to the consolidated results. Accounting Pronouncements Not Yet Adopted Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the SEC did not have, or are not expected to have, a significant impact on our present or future condensed consolidated financial statements.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Business Combination	Note 2 – Business Combination Business Combination Agreement and Amendments On April 29, 2018, we entered into a Business Combination Agreement for the Merger. The Business Combination Agreement was subsequently amended to provide that, following the closing of the Merger and the other transactions contemplated by the Business Combination Agreement (collectively, the “Transactions”), SoftBank Group Corp. (“SoftBank”) would indemnify us against certain specified matters and the loss of value arising out of or resulting from cessation of access to spectrum under certain circumstances and subject to certain limitations and qualifications. On February 20, 2020, T-Mobile, SoftBank and Deutsche Telekom AG (“DT”) entered into a letter agreement (the “Letter Agreement”). Pursuant to the Letter Agreement, SoftBank agreed to cause its applicable affiliates to surrender to T-Mobile, for no additional consideration, an aggregate of 48,751,557 shares of T-Mobile common stock (such number of shares, the “SoftBank Specified Shares Amount”), effective immediately following the Effective Time (as defined in the Business Combination Agreement), making SoftBank’s exchange ratio 11.31 shares of Sprint common stock for each share of T-Mobile common stock. This resulted in an effective exchange ratio of approximately 11.00 shares of Sprint common stock for each share of T-Mobile common stock immediately following the closing of the Merger, an increase from the originally agreed 9.75 shares. Sprint stockholders other than SoftBank received the original fixed exchange ratio of 0.10256 shares of T-Mobile common stock for each share of Sprint common stock, or the equivalent of approximately 9.75 shares of Sprint common stock for each share of T-Mobile common stock. The Letter Agreement requires T-Mobile to issue to SoftBank 48,751,557 shares of T-Mobile common stock, subject to the terms and conditions set forth in the Letter Agreement, for no additional consideration, if certain conditions are met. The issuance of these shares is contingent on the trailing 45-day volume-weighted average price per share of T-Mobile common stock on the NASDAQ Global Select Market being equal to or greater than $150.00, at any time during the period commencing on April 1, 2022 and ending on December 31, 2025. If the threshold price is not met, then none of the SoftBank Specified Shares Amount will be issued. Closing of Sprint Merger On April 1, 2020, we completed the Merger, and as a result, Sprint and its subsidiaries became wholly owned consolidated subsidiaries of T-Mobile. Sprint was the fourth-largest telecommunications company in the U.S. offering a comprehensive range of wireless and wireline communication products and services. As a combined company, we expect to be able to rapidly launch a broad and deep nationwide 5G network, accelerate innovation, increase competition in the U.S. wireless, video and broadband industries and achieve significant synergies and cost reductions by eliminating redundancies within the combined network as well as other business processes and operations. We combined the Sprint and T-Mobile operations under the T-Mobile brand nationwide on August 2, 2020. Upon completion of the Merger, each share of Sprint common stock was exchanged for 0.10256 shares of T-Mobile common stock, or 9.75 shares of Sprint common stock for each share of T-Mobile common stock. After adjustments, including the holdback of the SoftBank Specified Shares Amount and fractional shares, we issued 373,396,310 shares of T-Mobile common stock to Sprint stockholders. The fair value of the T-Mobile common stock provided in exchange for Sprint common stock was approximately $31.3 billion. Additional components of consideration included the repayment of certain of Sprint’s debt, replacement equity awards attributable to pre-combination services, contingent consideration and a cash payment received for certain reimbursed Merger expenses. Immediately following the closing of the Merger and the surrender of the SoftBank Specified Shares Amount, pursuant to the Letter Agreement described above, DT and SoftBank held, directly or indirectly, approximately 43.6% and 24.7%, respectively, of the outstanding T-Mobile common stock, with the remaining approximately 31.7% of the outstanding T-Mobile common stock held by other stockholders. Consideration Transferred The acquisition-date fair value of consideration transferred in the Merger totaled $40.8 billion, comprised of the following: (in millions) April 1, 2020 Fair value of T-Mobile common stock issued to Sprint stockholders (1) $ 31,328 Fair value of T-Mobile replacement equity awards attributable to pre-combination service (2) 323 Repayment of Sprint’s debt (including accrued interest and prepayment penalties) (3) 7,396 Value of contingent consideration (4) 1,882 Payment received from selling stockholder (5) (102) Total consideration exchanged $ 40,827 (1) Represents the fair value of T-Mobile common stock issued to Sprint stockholders pursuant to the Business Combination Agreement, less shares surrendered by SoftBank pursuant to the Letter Agreement. The fair value is based on 373,396,310 shares of Sprint common stock issued and outstanding as of March 31, 2020, an exchange ratio of 0.10256 shares of T-Mobile common stock per share of Sprint common stock, less 48,751,557 T-Mobile shares surrendered by SoftBank which are treated as contingent consideration, and the closing price per share of T-Mobile common stock on NASDAQ on March 31, 2020, of $83.90, as shares were transferred to Sprint stockholders prior to the opening of markets on April 1, 2020. (2) Equity-based awards held by Sprint employees prior to the acquisition date have been replaced with T-Mobile equity-based awards. The portion of the equity-based awards that relates to services performed by the employee prior to the acquisition date is included within consideration transferred, and includes stock options, restricted stock units and performance-based restricted stock units. (3) Represents the cash consideration paid concurrent with the close of the Merger to retire certain Sprint debt, as required by change in control provisions of the debt, plus interest and prepayment penalties. (4) Represents the fair value of the SoftBank Specified Shares Amount contingent consideration that may be issued as set forth in the Letter Agreement. (5) Represents receipt of a cash payment from SoftBank for certain expenses associated with the Merger and is presented in Cash paid for acquisition of companies, net of cash acquired within our Condensed Consolidated Statements of Cash Flows. The SoftBank Specified Shares Amount was determined to be contingent consideration with an acquisition-date fair value of $1.9 billion. We estimated the fair value using the income approach, a probability-weighted discounted cash flow model, whereby a Monte Carlo simulation method estimated the probability of different outcomes as the likelihood of achieving the 45-day volume-weighted average price threshold is not easily predicted. This fair value measurement is based on significant inputs not observable in the market and, therefore, represents a Level 3 measurement as defined in ASC 820. The key assumptions in applying the income approach include estimated future share-price volatility, which was based on historical market trends and estimated future performance of T-Mobile. The maximum amount of contingent consideration that could be issued to SoftBank has an estimated value of $7.3 billion, based on SoftBank Specified Shares Amount of 48,751,557 multiplied by the defined volume-weighted average price per share of $150.00. The contingent consideration that could be delivered to SoftBank is classified within equity and is not subject to remeasurement. Fair Value of Assets Acquired and Liabilities Assumed We accounted for the Merger as a business combination. The identifiable assets acquired and liabilities assumed of Sprint were recorded at their preliminary fair values as of the acquisition date and consolidated with those of T-Mobile. Assigning fair market values to the assets acquired and liabilities assumed at the date of an acquisition requires the use of significant judgment regarding estimates and assumptions. For the preliminary fair values of the assets acquired and liabilities assumed, we used the cost, income and market approaches, including market participant assumptions. The following table summarizes the preliminary fair values for each major class of assets acquired and liabilities assumed at the acquisition date. We retained the services of certified valuation specialists to assist with assigning estimated values to certain acquired assets and assumed liabilities. We are in the process of finalizing the valuation of the assets acquired and liabilities assumed including income tax related amounts. Therefore, the preliminary fair values set forth below are subject to further adjustment as additional information is obtained and the valuations are completed. (in millions) April 1, 2020 Cash and cash equivalents $ 2,214 Accounts receivable 1,650 Equipment installment plan receivables 1,024 Inventory 658 Prepaid expenses 140 Assets held for sale 1,908 Other current assets 642 Property and equipment 17,230 Operating lease right-of-use assets 6,583 Financing lease right-of-use assets 291 Goodwill 9,194 Spectrum licenses 45,400 Other intangible assets 6,325 Equipment installment plan receivables due after one year, net 247 Other assets (1) 541 Total assets acquired 94,047 Accounts payable and accrued liabilities 4,907 Short-term debt 2,760 Deferred revenue 508 Short-term operating lease liabilities 1,818 Short-term financing lease liabilities 8 Liabilities held for sale 475 Other current liabilities 650 Long-term debt 29,037 Tower obligations 950 Deferred tax liabilities 3,866 Operating lease liabilities 5,615 Financing lease liabilities 12 Other long-term liabilities 2,614 Total liabilities assumed 53,220 Total consideration transferred $ 40,827 (1) Included in Other assets acquired is $80 million in restricted cash. Amounts previously disclosed for the estimated values of certain acquired assets and liabilities assumed have been revised based on additional information arising subsequent to the initial valuation. These revisions to the estimated values did not have a significant impact on our Condensed Consolidated Statements of Comprehensive Income. Intangible Assets and Liabilities Goodwill with a provisionally assigned value of $9.2 billion represents the excess of the consideration transferred over the estimated fair values of assets acquired and liabilities assumed. The preliminary goodwill recognized includes synergies expected to be achieved from the operations of the combined company, the assembled workforce of Sprint and intangible assets that do not qualify for separate recognition. Expected synergies include the cost savings from the planned integration of network infrastructure, facilities, personnel and systems. None of the goodwill resulting from the Merger is deductible for tax purposes. All of the goodwill acquired is allocated to the Wireless reporting unit. Other intangible assets include $4.9 billion of subscriber relationships with a weighted-average useful life of eight years and tradenames of $207 million with a useful life of two years. Leased spectrum arrangements that have favorable (asset) and unfavorable (liability) terms compared to current market rates were provisionally assigned fair values of $790 million and $197 million, respectively, with 18 year and 19 year weighted average useful lives, respectively. The preliminary fair value of Spectrum licenses of $45.4 billion was estimated using the income approach and the Greenfield Method. This fair value measurement is based on significant inputs not observable in the market and, therefore, represents a Level 3 measurement as defined in ASC 820. The key assumptions in applying the income approach include the discount rate, market share, estimated capital and operating expenditures and forecasted long-term growth rates and service revenue over an estimated period of time for a hypothetical market participant that enters the wireless industry and builds a nationwide wireless network. Acquired Receivables The fair value of the assets acquired include Accounts receivable of $1.7 billion and EIP receivables of $1.3 billion. The unpaid principal balance under these contracts as of the Merger date was $1.7 billion and $1.6 billion, respectively. The difference between the fair value and the unpaid principal balance primarily represents amounts expected to be uncollectible. Indemnification Assets and Contingent Liabilities Pursuant to Amendment No 2. to the Business Combination Agreement, SoftBank agreed to indemnify us against certain specified matters and losses. As of September 30, 2020, we have recorded contingent liabilities and an offsetting indemnification asset for the expected reimbursement by SoftBank. The liabilities are presented in Accounts payable and accrued liabilities, and the indemnification asset is presented in Other current assets within our Condensed Consolidated Balance Sheets. Subsequent to September 30, 2020, we reached an agreement on certain matters, which will result in a payment of $200 million to resolve the FCC’s investigation. SoftBank has agreed to indemnify us for the settlement amount. We expect that any additional liabilities related to these indemnified matters would be indemnified and reimbursed by SoftBank. Transaction Costs We recognized transaction costs of $8 million and $30 million for the three months ended September 30, 2020 and 2019, respectively, and $192 million and $81 million for the nine months ended September 30, 2020 and 2019, respectively. These costs were associated with legal and professional services and were recognized as Selling, general and administrative expenses in our Condensed Consolidated Statements of Comprehensive Income. Pro Forma Information The following unaudited pro forma financial information gives effect to the Transactions as if they had been completed on January 1, 2019. The unaudited pro forma information was prepared in accordance with the requirements of ASC 805, which is a different basis than pro forma information prepared under Article 11 of Regulation S-X (“Article 11”). As such, they are not directly comparable with historical results for stand-alone T-Mobile prior to April 1, 2020, historical results for T-Mobile from April 1, 2020 that reflect the Transactions and are inclusive of the results and operations of Sprint, nor our previously provided pro forma financials prepared in accordance with Article 11. The pro forma results for the three and nine months ended September 30, 2020 and 2019, include the impact of several adjustments to previously reported operating results. The pro forma adjustments are based on historically reported transactions by the respective companies. The pro forma results do not include any anticipated synergies or other expected benefits of the acquisition. Three Months Ended September 30, Nine Months Ended September 30, (in millions, except per share amounts) 2020 2019 2020 2019 Total revenues $ 19,269 $ 17,243 $ 54,342 $ 52,322 Income (loss) from continuing operations 1,359 451 2,455 (628) Income from discontinued operations, net of tax — 393 677 1,239 Net income 1,359 849 3,132 623 Significant nonrecurring pro forma adjustments include: • Transaction costs of $550 million are assumed to have occurred on January 1, 2019, and are recognized as if incurred in the first quarter of 2019; • The Prepaid Business divested on July 1, 2020, is assumed to have been classified as discontinued operations as of January 1, 2019, and the related activities are presented in Income from discontinued operations, net of tax; • Permanent financing issued and debt redemptions occurring in connection with the closing of the Merger are assumed to have occurred on January 1, 2019, and historical interest expense associated with repaid borrowings is removed; • Tangible and intangible assets are assumed to be recorded at their preliminary assigned fair values as of the pro forma close date of January 1, 2019 and are depreciated or amortized over their estimated useful lives; and • Accounting policies of Sprint are conformed to those of T-Mobile including depreciation for leased devices, Brightstar distribution, amortization of costs to acquire a contract and certain lessee transactions as described in Note 1 - Summary of Significant Accounting Policies and Note 9 - Tower Obligations . The selected unaudited pro forma condensed combined financial information is provided for illustrative purposes only and does not purport to represent what the actual consolidated results of operations would have been had the Transactions actually occurred on January 1, 2019, nor do they purport to project the future consolidated results of operations. For the periods subsequent to the Merger close date, the acquired Sprint subsidiaries contributed total revenues of $7.2 billion and $13.5 billion to the three and nine months ended September 30, 2020, respectively, and operating income of $897 million and $912 million to the three and nine months ended September 30, 2020, respectively, that were included in our Condensed Consolidated Statements of Comprehensive Income. Financing In connection with the entry into the Business Combination Agreement, T-Mobile USA, Inc. (“T-Mobile USA”) entered into a commitment letter, dated as of April 29, 2018 (as amended and restated on May 15, 2018 and on September 6, 2019, the “Commitment Letter”). On April 1, 2020, in connection with the closing of the Merger, we drew down on our $19.0 billion New Secured Bridge Loan Facility and our $4.0 billion New Secured Term Loan Facility (each as defined below). We used the net proceeds from the draw-down of the secured facilities to refinance certain existing debt of us, Sprint and our and Sprint’s respective subsidiaries and for post-closing general corporate purposes of the combined company. See Note 8 – Debt for further information. In connection with the financing provided for in the Commitment Letter, we incurred certain fees payable to the financial institutions. On April 1, 2020, in connection with the closing of the Merger, we paid $355 million in Commitment Letter fees to certain financial institutions. See Note 8 – Debt for further information. In connection with the entry into the Business Combination Agreement, DT and T-Mobile USA entered into a Financing Matters Agreement, dated as of April 29, 2018 (the “Financing Matters Agreement”), pursuant to which DT agreed, among other things, to consent to, subject to certain conditions, amendments to certain existing debt owed to DT, in connection with the Merger. On April 1, 2020, in connection with the closing of the Merger, we made a payment for requisite consents to DT of $13 million. See Note 8 – Debt for further information. On May 18, 2018, under the terms and conditions described in the Consent Solicitation Statement dated as of May 14, 2018 (the “Consent Solicitation Statement”), we obtained consents necessary to effect amendments to certain existing debt of us and our subsidiaries. On April 1, 2020, in connection with the closing of the Merger, we made payments for requisite consents to third-party note holders of $95 million. See Note 8 – Debt for further information. Regulatory Matters The Transactions were the subject of various legal and regulatory proceedings involving a number of state and federal agencies. In connection with those proceedings and the approval of the Transactions, we have certain commitments and other obligations to various state and federal agencies and certain nongovernmental organizations. See Note 17 - Commitments and Contingencies for further information. Prepaid Transaction On July 26, 2019, we entered into the Asset Purchase Agreement with Sprint and DISH, pursuant to which, following the consummation of the Merger, DISH would acquire the Prepaid Business. On June 17, 2020, T-Mobile, Sprint and DISH entered into the First Amendment to the Asset Purchase Agreement. Pursuant to the First Amendment of the Asset Purchase Agreement, T-Mobile, Sprint and DISH agreed to proceed with the closing of the Prepaid Transaction in accordance with the Asset Purchase Agreement on July 1, 2020, subject to the terms and conditions of the Asset Purchase Agreement and the terms and conditions of the Consent Decree. On July 1, 2020, pursuant to the Asset Purchase Agreement, we completed the Prepaid Transaction. Upon closing of the Prepaid Transaction, we received $1.4 billion from DISH for the Prepaid Business, subject to a working capital adjustment. See Note 12 - Discontinued Operations for further information. Shenandoah Personal Communications Company Affiliate Relationship Sprint PCS (specifically Sprint Spectrum L.P.) is party to a variety of publicly filed agreements with Shenandoah Personal Communications Company (“Shentel”), pursuant to which Shentel is the exclusive provider of Sprint PCS’s wireless mobility communications network products in certain parts of Virginia, West Virginia, Kentucky, Ohio, and Pennsylvania that are home to approximately 1.1 million subscribers, as reported by Shentel as of June 30, 2020. Pursuant to one such agreement, the Sprint PCS Management Agreement, dated November 5, 1999 (as amended, supplemented and modified from time to time, the “Management Agreement”), Sprint PCS was granted an option to purchase Shentel’s wireless telecommunications assets. On August 26, 2020, Sprint, on behalf of and as the direct or indirect owner of Sprint PCS, exercised its option by delivering a binding notice of exercise to Shentel. The purchase price for the Shentel wireless telecommunications assets to be purchased by Sprint will be determined through the appraisal process prescribed in the Management Agreement. We expect the appraisal process to be completed in the first quarter of 2021.

Receivables and Expected Credit

Receivables and Expected Credit Losses	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Receivables and Expected Credit Losses	Note 3 – Receivables and Expected Credit Losses Our portfolio of receivables is comprised of two portfolio segments: accounts receivable and EIP receivables. Accounts Receivable Portfolio Segment Our accounts receivable segment primarily consists of amounts currently due from customers, including service and leased device receivables, handset insurance administrators, wholesale partners, third-party retail channels and other carriers. We estimate expected credit losses associated with our accounts receivable portfolio using an aging schedule methodology that utilizes historical information and current conditions to develop expected credit losses by aging bucket, including for receivables that are not past due. To determine the appropriate credit loss percentages by aging bucket, we consider a number of factors, including our overall historical credit losses, net of recoveries and timely payment experience as well as current collection trends such as write-off frequency and severity, credit quality of the customer base, and other qualitative factors such as macro-economic conditions, including the expected economic impacts of the COVID-19 pandemic. We consider the need to adjust our estimate of expected credit losses for reasonable and supportable forecasts of future economic conditions. To do so, we monitor professional forecasts of changes in real U.S. gross domestic product and forecasts of consumer credit behavior for comparable credit exposures. We also periodically evaluate other economic indicators such as unemployment rates to assess their level of correlation with our historical credit loss statistics. EIP Receivables Portfolio Segment Based upon customer credit profiles at the time of customer origination, we classify the EIP receivables segment into two customer classes of “Prime” and “Subprime.” Prime customer receivables are those with lower credit risk and Subprime customer receivables are those with higher credit risk. Customers may be required to make a down payment on their equipment purchases. In addition, certain customers within the Subprime category are required to pay an advance deposit. To determine a customer’s credit profile, we use a proprietary credit scoring model that measures the credit quality of a customer using several factors, such as credit bureau information, consumer credit risk scores and service and device plan characteristics. Installment loans acquired in the Merger are included in EIP receivables. We applied our proprietary credit scoring model to the customers acquired in the Merger with an outstanding EIP receivable balance. Based on tenure, consumer credit risk score and credit profile, these acquired customers were classified into our customer classes of Prime or Subprime. Our proprietary credit scoring model is applied to all EIP arrangements originated after the Merger close date. The following table summarizes the EIP receivables, including imputed discounts and related allowance for credit losses: (in millions) September 30, 2020 December 31, EIP receivables, gross (1) $ 5,018 $ 4,582 Unamortized imputed discount (248) (299) EIP receivables, net of unamortized imputed discount 4,770 4,283 Allowance for credit losses (2) (289) (100) EIP receivables, net of allowance for credit losses and imputed discount $ 4,481 $ 4,183 Classified on the balance sheet as: Equipment installment plan receivables, net of allowance for credit losses and imputed discount $ 3,083 $ 2,600 Equipment installment plan receivables due after one year, net of allowance for credit losses and imputed discount 1,398 1,583 EIP receivables, net of allowance for credit losses and imputed discount $ 4,481 $ 4,183 (1) Through the Merger, we acquired EIP receivables with a fair value of $1.3 billion as of April 1, 2020. As they were recorded at fair value, an imputed discount was not recognized on the acquired receivables. (2) Allowance for credit losses as of September 30, 2020 was impacted by the cumulative effect of initially applying the new credit loss standard on our receivables portfolio on January 1, 2020, which resulted in an increase to our allowance for credit losses of $91 million. We manage our EIP receivables portfolio using delinquency and customer credit class as key credit quality indicators. As a part of the adoption of the new credit loss standard, we now disclose our EIP receivables portfolio disaggregated by origination year. EIP receivables acquired through the Merger are also presented by origination year. The following table presents the amortized cost of our EIP receivables by delinquency status, customer credit class, and year of origination as of September 30, 2020. Originated in 2020 Originated in 2019 Originated prior to 2019 Total EIP Receivables, net of (in millions) Prime Subprime Prime Subprime Prime Subprime Prime Subprime Grand total Current - 30 days past due $ 1,540 $ 1,453 $ 766 $ 654 $ 193 $ 66 $ 2,499 $ 2,173 $ 4,672 31 - 60 days past due 9 19 8 13 1 1 18 33 51 61 - 90 days past due 2 7 2 5 1 1 5 13 18 More than 90 days past due 3 8 4 10 1 3 8 21 29 EIP receivables, net of unamortized imputed discount $ 1,554 $ 1,487 $ 780 $ 682 $ 196 $ 71 $ 2,530 $ 2,240 $ 4,770 We estimate expected credit losses on our EIP receivables by using historical data adjusted for current conditions to calculate default probabilities for our outstanding EIP loans. We consider various risk characteristics when calculating default probabilities, such as how long such loans have been outstanding, customer credit ratings, customer tenure, delinquency status and other correlated variables identified through statistical analyses. We multiply these estimated default probabilities by our estimated loss given default, which considers recoveries. As we do for our accounts receivable portfolio segment, we consider the need to adjust our estimate of expected losses on EIP receivables for reasonable and supportable forecasts of economic conditions through monitoring of external professional forecasts and periodic internal statistical analyses, including the expected economic impacts of the COVID-19 pandemic. For EIP receivables acquired in the Merger, the difference between the fair value and unpaid principal balance of the loan at the acquisition date is accreted to interest income over the contractual life of the loan using the effective interest method. EIP receivables had a combined weighted average effective interest rate of 7.6% and 8.8% as of September 30, 2020 and December 31, 2019, respectively. Activity for the nine months ended September 30, 2020 and 2019, in the allowance for credit losses and unamortized imputed discount balances for the accounts receivable and EIP receivables segments were as follows: September 30, 2020 September 30, 2019 (in millions) Accounts Receivable Allowance EIP Receivables Allowance Total Accounts Receivable Allowance EIP Receivables Allowance Total Allowance for credit losses and imputed discount, beginning of period $ 61 $ 399 $ 460 $ 67 $ 449 $ 516 Beginning balance adjustment due to implementation of the new credit loss standard — 91 91 — — — Bad debt expense 261 228 489 51 167 218 Write-offs, net of recoveries (114) (130) (244) (57) (185) (242) Change in imputed discount on short-term and long-term EIP receivables N/A 60 60 N/A 91 91 Impact on the imputed discount from sales of EIP receivables N/A (111) (111) N/A (127) (127) Allowance for credit losses and imputed discount, end of period $ 208 $ 537 $ 745 $ 61 $ 395 $ 456 Off-Balance-Sheet Credit Exposures We do not have material, unmitigated off-balance-sheet credit exposures as of September 30, 2020. In connection with the sales of certain service and EIP accounts receivable pursuant to the sale arrangements, we have deferred purchase price assets included in our Condensed Consolidated Balance Sheets measured at fair value that are based on a discounted cash flow model using unobservable Level 3 inputs, including customer default rates and credit worthiness, dilutions and recoveries. See Note 4 – Sales of Certain Receivables for further information.

Sales of Certain Receivables

Sales of Certain Receivables	9 Months Ended
	Sep. 30, 2020
Transfers and Servicing [Abstract]
Sales of Certain Receivables	Note 4 – Sales of Certain Receivables We have entered into transactions to sell certain service accounts receivable and EIP receivables. The transactions, including our continuing involvement with the sold receivables and the respective impacts to our condensed consolidated financial statements, are described below. In conjunction with the Merger, the total principal amount outstanding under Sprint’s accounts receivable facility of $2.3 billion was repaid on April 1, 2020, and the facility was terminated. Sales of Service Accounts Receivable Overview of the Transaction In 2014, we entered into an arrangement to sell certain service accounts receivable on a revolving basis (the “service receivable sale arrangement”). The maximum funding commitment of the service receivable sale arrangement is $950 million, and the facility expires in March 2021. As of September 30, 2020 and December 31, 2019, the service receivable sale arrangement provided funding of $828 million and $924 million, respectively. Sales of receivables occur daily and are settled on a monthly basis. The receivables consist of service charges currently due from customers and are short-term in nature. In connection with the service receivable sale arrangement, we formed a wholly owned subsidiary, which qualifies as a bankruptcy remote entity, to sell service accounts receivable (the “Service BRE”). The Service BRE does not qualify as a VIE, and due to the significant level of control we exercise over the entity, it is consolidated. Pursuant to the service receivable sale arrangement, certain of our wholly owned subsidiaries transfer selected receivables to the Service BRE. The Service BRE then sells the receivables to an unaffiliated entity (the “Service VIE”), which was established to facilitate the sale of beneficial ownership interests in the receivables to certain third parties. Variable Interest Entity We determined that the Service VIE qualifies as a VIE as it lacks sufficient equity to finance its activities. We have a variable interest in the Service VIE but are not the primary beneficiary as we lack the power to direct the activities that most significantly impact the Service VIE’s economic performance. Those activities include committing the Service VIE to legal agreements to purchase or sell assets, selecting which receivables are purchased in the service receivable sale arrangement, determining whether the Service VIE will sell interests in the purchased service receivables to other parties, funding of the entity and servicing of receivables. We do not hold the power to direct the key decisions underlying these activities. For example, while we act as the servicer of the sold receivables, which is considered a significant activity of the Service VIE, we are acting as an agent in our capacity as the servicer, and the counterparty to the service receivable sale arrangement has the ability to remove us as the servicing agent of the receivables at will with no recourse available to us. As we have determined we are not the primary beneficiary, the balances and results of the Service VIE are not included in our condensed consolidated financial statements. The following table summarizes the carrying amounts and classification of assets, which consist primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to our variable interest in the Service VIE: (in millions) September 30, December 31, Other current assets $ 386 $ 350 Accounts payable and accrued liabilities 65 25 Other current liabilities 371 342 Sales of EIP Receivables Overview of the Transaction In 2015, we entered into an arrangement to sell certain EIP accounts receivable on a revolving basis (the “EIP sale arrangement”). The maximum funding commitment of the sale arrangement is $1.3 billion. In February 2020, we amended the sale arrangement to provide for an alternative advance rate methodology for the EIP accounts receivables sold in the sale arrangement and to make certain other administrative changes. On April 30, 2020, we agreed with the purchaser banks to update our collection policies to temporarily allow for flexibility for modifications to the accounts receivable sold that are impacted by COVID-19 and exclusion of such accounts receivable from all pool performance triggers. Subsequent to September 30, 2020, on November 2, 2020, we extended the scheduled expiration date of the EIP sale arrangement to November 18, 2021. As of both September 30, 2020 and December 31, 2019, the EIP sale arrangement provided funding of $1.3 billion. Sales of EIP receivables occur daily and are settled on a monthly basis. In connection with this EIP sale arrangement, we formed a wholly owned subsidiary, which qualifies as a bankruptcy remote entity (the “EIP BRE”). Pursuant to the EIP sale arrangement, our wholly owned subsidiary transfers selected receivables to the EIP BRE. The EIP BRE then sells the receivables to a non-consolidated and unaffiliated third-party entity over which we do not exercise any level of control, nor does the third-party entity qualify as a VIE. Variable Interest Entity We determined that the EIP BRE is a VIE as its equity investment at risk lacks the obligation to absorb a certain portion of its expected losses. We have a variable interest in the EIP BRE and have determined that we are the primary beneficiary based on our ability to direct the activities which most significantly impact the EIP BRE’s economic performance. Those activities include selecting which receivables are transferred into the EIP BRE and sold in the EIP sale arrangement and funding of the EIP BRE. Additionally, our equity interest in the EIP BRE obligates us to absorb losses and gives us the right to receive benefits from the EIP BRE that could potentially be significant to the EIP BRE. Accordingly, we include the balances and results of operations of the EIP BRE in our condensed consolidated financial statements. The following table summarizes the carrying amounts and classification of assets, which consist primarily of the deferred purchase price, and liabilities included in our Condensed Consolidated Balance Sheets that relate to the EIP BRE: (in millions) September 30, 2020 December 31, Other current assets $ 353 $ 344 Other assets 109 89 Other long-term liabilities 8 18 In addition, the EIP BRE is a separate legal entity with its own separate creditors who will be entitled, prior to any liquidation of the EIP BRE, to be satisfied prior to any value in the EIP BRE becoming available to us. Accordingly, the assets of the EIP BRE may not be used to settle our general obligations and creditors of the EIP BRE have limited recourse to our general credit. Sales of Receivables The transfers of service receivables and EIP receivables to the non-consolidated entities are accounted for as sales of financial assets. Once identified for sale, the receivable is recorded at the lower of cost or fair value. Upon sale, we derecognize the net carrying amount of the receivables. We recognize the cash proceeds received upon sale in Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows. We recognize proceeds net of the deferred purchase price, consisting of a receivable from the purchasers that entitles us to certain collections on the receivables. We recognize the collection of the deferred purchase price in Net cash used in investing activities in our Condensed Consolidated Statements of Cash Flows as Proceeds related to beneficial interests in securitization transactions. The deferred purchase price represents a financial asset that is primarily tied to the creditworthiness of the customers and which can be settled in such a way that we may not recover substantially all of our recorded investment, due to default by the customers on the underlying receivables. We elected, at inception, to measure the deferred purchase price at fair value with changes in fair value included in Selling, general and administrative expense in our Condensed Consolidated Statements of Comprehensive Income. The fair value of the deferred purchase price is determined based on a discounted cash flow model which uses primarily unobservable inputs (Level 3 inputs), including customer default rates. As of September 30, 2020 and December 31, 2019, our deferred purchase price related to the sales of service receivables and EIP receivables was $846 million and $781 million, respectively. The following table summarizes the impact of the sale of certain service receivables and EIP receivables in our Condensed Consolidated Balance Sheets: (in millions) September 30, 2020 December 31, Derecognized net service receivables and EIP receivables $ 2,535 $ 2,584 Other current assets 739 694 of which, deferred purchase price 737 692 Other long-term assets 109 89 of which, deferred purchase price 109 89 Accounts payable and accrued liabilities 65 25 Other current liabilities 371 342 Other long-term liabilities 8 18 Net cash proceeds since inception 1,845 1,944 Of which: Change in net cash proceeds during the year-to-date period (99) 65 Net cash proceeds funded by reinvested collections 1,944 1,879 We recognized a gain from sales of receivables, including adjustments to the receivables’ fair values and changes in fair value of the deferred purchase price, of $18 million and a loss from sales of receivables of $28 million for the three months ended September 30, 2020 and 2019, respectively, and losses of $37 million and $91 million for the nine months ended September 30, 2020 and 2019, respectively, in Selling, general and administrative expense in our Condensed Consolidated Statements of Comprehensive Income. Continuing Involvement Pursuant to the sale arrangements described above, we have continuing involvement with the service receivables and EIP receivables we sell as we service the receivables and are required to repurchase certain receivables, including ineligible receivables, aged receivables and receivables where write-off is imminent. We continue to service the customers and their related receivables, including facilitating customer payment collection, in exchange for a monthly servicing fee. As the receivables are sold on a revolving basis, the customer payment collections on sold receivables may be reinvested in new receivable sales. At the direction of the purchasers of the sold receivables, we apply the same policies and procedures while servicing the sold receivables as we apply to our owned receivables, and we continue to maintain normal relationships with our customers. Pursuant to the EIP sale arrangement, under certain circumstances, we are required to deposit cash or replacement EIP receivables primarily for contracts terminated by customers under our JUMP! On Demand program. In addition, we have continuing involvement with the sold receivables as we may be responsible for absorbing additional credit losses pursuant to the sale arrangements. Our maximum exposure to loss related to the involvement with the service receivables and EIP receivables sold under the sale arrangements was $1.1 billion as of September 30, 2020. The maximum exposure to loss, which is a required disclosure under U.S. GAAP, represents an estimated loss that would be incurred under severe, hypothetical circumstances whereby we would not receive the deferred purchase price portion of the contractual proceeds withheld by the purchasers and would also be required to repurchase the maximum amount of receivables pursuant to the sale arrangements without consideration for any recovery. We believe the probability of these circumstances occurring is remote and the maximum exposure to loss is not an indication of our expected loss.

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	Note 5 – Property and Equipment The components of property and equipment were as follows: (in millions) Useful Lives September 30, 2020 December 31, Land $ 236 $ — Buildings and equipment Up to 40 years 3,872 2,587 Wireless communications systems Up to 20 years 45,666 34,353 Leasehold improvements Up to 12 years 1,750 1,345 Capitalized software Up to 10 years 15,703 12,705 Leased wireless devices Up to 19 months 7,436 1,139 Construction in progress 4,180 2,973 Accumulated depreciation and amortization (40,276) (33,118) Property and equipment, net $ 38,567 $ 21,984 Total depreciation expense relating to property and equipment and financing lease right-of-use assets was $3.8 billion and $1.7 billion for the three months ended September 30, 2020 and 2019, respectively, and $9.2 billion and $4.8 billion for the nine months ended September 30, 2020 and 2019, respectively. These amounts include depreciation expense related to leased wireless devices of $1.0 billion and $108 million for the three months ended September 30, 2020 and 2019 respectively, and $2.1 billion and $417 million for the nine months ended September 30, 2020 and 2019, respectively. We capitalize interest associated with the acquisition or construction of certain property and equipment and spectrum intangible assets. We recognized capitalized interest of $108 million and $118 million for the three months ended September 30, 2020 and 2019, respectively, and $339 million and $361 million for the nine months ended September 30, 2020 and 2019, respectively. Asset retirement obligations are primarily for certain legal obligations to remediate leased property on which our network infrastructure and administrative assets are located. Activity in our asset retirement obligations was as follows: (in millions) Nine Months Ended September 30, 2020 Twelve Months Ended Asset retirement obligations, beginning of year $ 659 $ 609 Fair value of liabilities acquired through Merger 1,062 — Liabilities incurred 9 35 Liabilities settled (16) (2) Accretion expense 37 32 Changes in estimated cash flows — (15) Asset retirement obligations, end of period $ 1,751 $ 659 Classified on the balance sheet as: Other long-term liabilities $ 1,751 $ 659 The corresponding assets, net of accumulated depreciation, related to asset retirement obligations were $965 million and $159 million as of September 30, 2020 and December 31, 2019, respectively. Postpaid Billing System Impairment In connection with the continuing integration of the businesses following the Merger, we evaluated the long-term billing system architecture strategy for our postpaid customers. In order to facilitate customer migration from the Sprint legacy billing platform, our postpaid billing system replacement plan and associated development will no longer serve our future needs. As a result, we recorded a non-cash impairment of $200 million related to capitalized software development costs for the nine months ended September 30, 2020, all of which relates to the impairment recognized during the three months ended June 30, 2020. The expense is included within Impairment expense in our Condensed Consolidated Statements of Comprehensive Income. There were no impairments recognized for the three and nine months ended September 30, 2019.

Goodwill, Spectrum License Tran

Goodwill, Spectrum License Transactions and Other Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Spectrum License Transactions and Other Intangible Assets	Note 6 – Goodwill, Spectrum License Transactions and Other Intangible Assets Goodwill The changes in the carrying amount of goodwill for the nine months ended September 30, 2020 and year ended December 31, 2019, are as follows: (in millions) Goodwill Historical goodwill, net of accumulated impairment losses of $10,766 $ 1,901 Goodwill from acquisition in 2019 29 Balance as of December 31, 2019 1,930 Goodwill from acquisition of Sprint 9,194 Layer3 goodwill impairment (218) Balance as of September 30, 2020 $ 10,906 Accumulated impairment losses at September 30, 2020 $ (10,985) On April 1, 2020, we completed our Merger with Sprint, which was accounted for as a business combination resulting in $9.2 billion in goodwill. The acquired goodwill was allocated to the Wireless reporting unit and will be tested for impairment at this level. See Note 2 - Business Combination for further information. Goodwill Impairment Assessment Certain non-financial assets, including goodwill and indefinite-lived intangible assets, are not required to be measured at fair value on a recurring basis and are reported at carrying value. However, these assets are required to be assessed for impairment when events or circumstances indicate that carrying value may not be recoverable, and at least annually for goodwill and indefinite-lived intangible assets. Accordingly, the nonrecurring measurement of the fair value of these assets are classified within Level 3 of the fair value hierarchy. In the event an impairment is required, the asset is adjusted to fair value, using market-based assumptions. Our enhanced in-home broadband opportunity following the Merger, along with the acquisition of certain content rights, has created a strategic shift in our TVision TM Home service offering, allowing us the ability to develop a video product that will be complementary to the in-home broadband offering. As a result of the change in the stand-alone product offering plans and timing, we completed an interim goodwill impairment analysis for the Layer3 reporting unit and recognized a goodwill impairment of $218 million for the nine months ended September 30, 2020, all of which relates to the impairment recognized during the three months ended June 30, 2020. The expense is included within Impairment expense in our Condensed Consolidated Statements of Comprehensive Income. There were no goodwill impairments recognized for the three and nine months ended September 30, 2019. Application of the goodwill impairment test requires judgment including the determination of the fair value of the reporting unit. We employed an income approach to assess the fair value of the Layer3 reporting unit based on the present value of estimated future cash flows. Inherent in our preparation of cash flow projections are assumptions and estimates derived from a review of our business plans, expected growth rates, cost of capital and tax rates. We also made certain forecasts about future business strategies and economic conditions, market data, and other assumptions, such as estimates of subscribers for TVision services, average revenue and content cost per subscriber. The discount rate used was based on the weighted average cost of capital adjusted for the risk associated with business-specific characteristics and the uncertainty related to the business’s ability to execute on the projected cash flows. Intangible Assets Identifiable Intangible Assets Acquired The following table summarizes the fair value of the intangible assets acquired in the Merger: Weighted Average Useful Life (in years) Fair Value as of April 1, 2020 Spectrum licenses Indefinite-lived $ 45,400 Tradenames (1) 2 years 207 Customer relationships 8 years 4,900 Favorable spectrum leases 18 years 790 Patent rights 7 years 51 Other intangible assets 7 years 377 Total intangible assets acquired $ 51,725 (1) Tradenames include the Sprint brand Spectrum licenses are issued for a fixed period of time, typically up to 15 years; however, the FCC has granted license renewals routinely and at a nominal cost. The spectrum licenses acquired expire at various dates and we believe we will be able to meet all requirements necessary to secure renewal of our spectrum licenses at a nominal cost. Moreover, we determined that there are currently no legal, regulatory, contractual, competitive, economic or other factors that limit the useful lives of our spectrum licenses. Therefore, we determined the spectrum licenses should be treated as indefinite-lived intangible assets. The fair value of spectrum licenses includes the value associated with aggregating a nationwide portfolio of owned and leased spectrum. Favorable spectrum leases represent a lease contract where the market rate is higher than the future contractual lease payments. We lease this spectrum from third parties who hold the spectrum licenses. As these contracts pertain to intangible assets, they are excluded from the lease accounting guidance (ASC 842) and are accounted for as service contracts in which the expense is recognized on a straight-line basis over the lease team. Favorable spectrum leases of $790 million were recorded as an intangible asset as a result of purchase accounting and will be amortized on a straight-line basis over the associated remaining lease term. Additionally, we recognized unfavorable spectrum lease liabilities of $197 million, which are also amortized over their respective remaining lease terms and are included in Other liabilities in our Condensed Consolidated Balance Sheets. The customer relationships intangible assets represent the value associated with the acquired Sprint customers. The customer relationship intangible assets are amortized using the sum-of-the-years digits method over periods of up to eight years. Other intangible assets are amortized over the remaining period that the asset is expected to provide benefit to us. Spectrum Licenses The following table summarizes our spectrum license activity for the nine months ended September 30, 2020: (in millions) Nine Months Ended September 30, 2020 Spectrum licenses, beginning of year $ 36,465 Spectrum license acquisitions 1,006 Spectrum licenses acquired in Merger 45,400 Costs to clear spectrum 20 Spectrum licenses, end of period $ 82,891 Spectrum Transactions In March 2020, the FCC announced that we were the winning bidder of 2,384 licenses in Auction 103 (37/39 GHz and 47 GHz spectrum bands) for an aggregate price of $873 million, net of an incentive payment of $59 million. At the inception of Auction 103 in October 2019, we deposited $82 million with the FCC. Upon conclusion of Auction 103 in March 2020, we made a down payment of $93 million for the purchase price of the licenses won in the auction. On April 8, 2020, we paid the FCC the remaining $698 million of the purchase price for the licenses won in the auction. Prior to the Merger, the FCC announced that Sprint was the winning bidder of 127 licenses in Auction 103 (37/39 GHz and 47 GHz spectrum bands). All payments related to the licenses won were made by Sprint prior to the Merger. The licenses are included in Spectrum licenses in our Condensed Consolidated Balance Sheets as of September 30, 2020. Cash payments to acquire spectrum licenses and payments for costs to clear spectrum are included in Refunds (purchases) of spectrum licenses and other intangible assets, including deposits in our Condensed Consolidated Statements of Cash Flows for the three and nine months ended September 30, 2020. In April 2020, we acquired FCC licenses in the 800 MHz, 1.9 GHz, and 2.5 GHz bands as part of the Merger with Sprint at an estimated fair value of approximately $45.4 billion. See Note 2 - Business Combination for further information. Other Intangible Assets The components of Other intangible assets were as follows: Useful Lives September 30, 2020 December 31, 2019 (in millions) Gross Amount Accumulated Amortization Net Amount Gross Amount Accumulated Amortization Net Amount Customer relationships Up to 8 years $ 6,004 $ (1,681) $ 4,323 $ 1,104 $ (1,104) $ — Tradenames and patents Up to 19 years 595 (364) 231 323 (258) 65 Favorable spectrum leases Up to 27 years 790 (23) 767 — — — Other Up to 10 years 477 (138) 339 100 (50) 50 Other intangible assets $ 7,866 $ (2,206) $ 5,660 $ 1,527 $ (1,412) $ 115 Amortization expense for intangible assets subject to amortization was $383 million and $18 million for the three months ended September 30, 2020 and 2019, respectively, and $794 million and $53 million for the nine months ended September 30, 2020 and 2019, respectively. The estimated aggregate future amortization expense for intangible assets subject to amortization are summarized below: (in millions) Estimated Future Amortization Twelve Months Ending September 30, 2021 $ 1,318 2022 1,040 2023 866 2024 709 2025 551 Thereafter 1,176 Total $ 5,660 Substantially all of the estimated future amortization expense is associated with intangible assets acquired in the Merger.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 7 – Fair Value Measurements The carrying values of Cash and cash equivalents, Accounts receivable, Accounts receivable from affiliates, Accounts payable and accrued liabilities and borrowings under vendor financing arrangements with our primary network equipment suppliers approximate fair value due to the short-term maturities of these instruments. Derivative Financial Instruments Periodically, we use derivatives to manage exposure to market risk, such as interest rate risk. We designate certain derivatives as hedging instruments in a qualifying hedge accounting relationship (cash flow hedge) to help minimize significant, unplanned fluctuations in cash flows caused by interest rate volatility. We do not use derivatives for trading or speculative purposes. Interest Rate Lock Derivatives In October 2018, we entered into interest rate lock derivatives with notional amounts of $9.6 billion. In November 2019, we extended the mandatory termination date on our interest rate lock derivatives to June 3, 2020. For the three months ended March 31, 2020, we made net collateral transfers to certain of our derivative counterparties totaling $580 million, which included variation margin transfers to (or from) such derivative counterparties based on daily market movements. No amounts were transferred in the three months ended June 30, 2020, or in the three months ended September 30, 2020. These collateral transfers are included in Net cash related to derivative contracts under collateral exchange arrangements within Net cash used in investing activities in our Condensed Consolidated Statements of Cash Flows. The net collateral transfers to certain of our derivative counterparties totaled $632 million for the three months ended December 31, 2019, and was presented in Other current assets in our Condensed Consolidated Balance Sheets. There was no collateral receivable balance as of September 30, 2020. We record interest rate lock derivatives on our Condensed Consolidated Balance Sheets at fair value that is derived primarily from observable market data, including yield curves. Interest rate lock derivatives were classified as Level 2 in the fair value hierarchy. Cash flows associated with qualifying hedge derivative instruments are presented in the same category on the Condensed Consolidated Statements of Cash Flows as the item being hedged. The fair value of interest rate lock derivatives was a liability of $1.2 billion as of December 31, 2019, and was included in Other current liabilities in our Condensed Consolidated Balance Sheets. Aggregate changes in fair value, net of tax, of $1.6 billion and $868 million are presented in Accumulated other comprehensive loss as of September 30, 2020 and December 31, 2019, respectively. Between April 2 to April 6, 2020, in connection with the issuance of an aggregate of $19.0 billion in Senior Secured Notes bearing interest rates ranging from 3.500% to 4.500% and maturing in 2025 through 2050, we terminated our interest rate lock derivatives. See Note 8 - Debt for further information regarding the issuance of Senior Secured Notes. At the time of termination, the interest rate lock derivatives were a liability of $2.3 billion, of which $1.2 billion was cash-collateralized. The cash flows associated with the settlement of interest rate lock derivatives are presented on a gross basis in our Condensed Consolidated Statements of Cash Flows, with the total cash payments to settle the swaps of $2.3 billion presented in changes in Other current and long-term liabilities within Net cash provided by operating activities and the return of cash collateral of $1.2 billion presented as an inflow in Net cash related to derivative contracts under collateral exchange arrangements within Net cash used in investing activities. Upon the issuance of debt to which the hedged interest rate risk related, we began amortizing the Accumulated other comprehensive loss with the derivatives into Interest expense in a manner consistent with how the hedged interest payments affect earnings. For the three and nine months ended September 30, 2020, $44 million and $83 million, respectively, was amortized from Accumulated other comprehensive loss into Interest expense in the Condensed Consolidated Statements of Comprehensive Income. We expect to amortize $185 million of the Accumulated other comprehensive loss associated with the derivatives into interest expense over the next 12 months. Deferred Purchase Price Assets In connection with the sales of certain service and EIP accounts receivable pursuant to the sale arrangements, we have deferred purchase price assets measured at fair value that are based on a discounted cash flow model using unobservable Level 3 inputs, including customer default rates. See Note 4 – Sales of Certain Receivables for further information. The carrying amounts of our deferred purchase price assets, which are measured at fair value on a recurring basis and included in our Condensed Consolidated Balance Sheets, were $846 million and $781 million at September 30, 2020, and December 31, 2019, respectively. Fair value was equal to carrying amount at September 30, 2020, and December 31, 2019. Debt The fair value of our Senior Unsecured Notes, Senior Secured Notes, and Secured Term Loan Facility to third parties was determined based on quoted market prices in active markets, and therefore were classified as Level 1 within the fair value hierarchy. The fair values of our Senior Notes to affiliates and Incremental Term Loan Facility to affiliates were determined based on a discounted cash flow approach using market interest rates of instruments with similar terms and maturities and an estimate for our standalone credit risk. Accordingly, our Senior Notes to affiliates and Incremental Term Loan Facility to affiliates were classified as Level 2 within the fair value hierarchy. Although we have determined the estimated fair values using available market information and commonly accepted valuation methodologies, considerable judgment was required in interpreting market data to develop fair value estimates for the Senior Notes to affiliates and Incremental Term Loan Facility to affiliates. The fair value estimates were based on information available as of September 30, 2020 and December 31, 2019. As such, our estimates are not necessarily indicative of the amount we could realize in a current market exchange. The carrying amounts and fair values of our short-term and long-term debt included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy September 30, 2020 December 31, 2019 (in millions) Carrying Amount (1) Fair Value (1) Carrying Amount (1) Fair Value (1) Liabilities: Senior Unsecured Notes to third parties 1 $ 30,078 $ 31,906 $ 10,958 $ 11,479 Senior Notes to affiliates 2 4,711 4,981 9,986 10,366 Senior Secured Notes to third parties 1 27,778 31,105 — — Incremental Term Loan Facility to affiliates 2 — — 4,000 4,000 Secured Term Loan Facility to third parties 1 3,890 3,990 — — (1) Excludes $312 million and $25 million as of September 30, 2020 and December 31, 2019, respectively, in vendor financing arrangements and other debt as the carrying values approximate fair value primarily due to the short-term maturities of these instruments. Guarantee Liabilities We offer device trade-in programs that provide eligible customers a specified-price trade-in right to upgrade their device. For customers who enroll in these programs, we recognize a liability and reduce revenue for the portion of revenue which represents the estimated fair value of the specified-price trade-in right guarantee, incorporating the expected probability and timing of handset upgrade and the estimated fair value of the handset which is returned. Accordingly, our guarantee liabilities were classified as Level 3 within the fair value hierarchy. When customers upgrade their device, the difference between the EIP balance credit to the customer and the fair value of the returned device is recorded against the guarantee liabilities. Guarantee liabilities are included in Other current liabilities in our Condensed Consolidated Balance Sheets. The carrying amounts of our guarantee liabilities measured at fair value on a non-recurring basis included in our Condensed Consolidated Balance Sheets were $45 million and $62 million as of September 30, 2020 and December 31, 2019, respectively. The total estimated remaining gross EIP receivable balances of all enrolled handset upgrade program customers, which are the remaining EIP amounts underlying the trade-in right guarantee, including EIP receivables that have been sold, was $2.9 billion as of September 30, 2020. This is not an indication of our expected loss exposure as it does not consider the expected fair value of the used handset or the probability and timing of the trade-in.

Debt

Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt	Note 8 - Debt The following table sets forth the debt balances and activity as of, and for the nine months ended, September 30, 2020 : (in millions) December 31, 2019 Proceeds from Issuances and Borrowings (1) Assumed Debt (2) Note Redemptions (1) Repayments (3) Reclassifications (1) Other (4) September 30, 2020 Short-term debt $ 25 $ 18,943 $ 2,760 $ (21,413) $ (2,355) $ 5,696 $ 57 $ 3,713 Long-term debt 10,958 26,595 29,037 — (2,310) (5,696) (239) 58,345 Total debt to third parties 10,983 45,538 31,797 (21,413) (4,665) — (182) 62,058 Short-term debt to affiliates — — — (3,235) — 3,231 4 — Long-term debt to affiliates 13,986 (13) — (6,041) — (3,231) 10 4,711 Total debt $ 24,969 $ 45,525 $ 31,797 $ (30,689) $ (4,665) $ — $ (168) $ 66,769 (1) Issuances and borrowings, note redemptions, and reclassifications are recorded net of related issuance costs, discounts and premiums. Includes the issuance of $200 million in vendor financing agreements and other debt as well as payments for requisite consents to DT and third-party note holders of $13 million and $95 million, respectively, made on April 1, 2020 in connection with the closing of the Merger, which were recognized as a reduction to Long-term debt in our Condensed Consolidated Balance Sheets. (2) In connection with the Merger, we assumed certain of Sprint’s indebtedness, as described below. (3) In conjunction with the Merger, the total principal amount outstanding under Sprint’s accounts receivable facility of $2.3 billion was repaid on April 1, 2020, and the facility was terminated. (4) Other includes the amortization of premiums, discounts, debt issuance costs and consent fees. Issuances and Borrowings During the nine months ended September 30, 2020, we issued the following Senior Secured Notes and entered into the following Secured loan facilities: (in millions) Principal Issuances Discounts and Issuance Costs Net Proceeds from Issuance of Long-Term Debt Issue Date 3.500% Senior Secured Notes due 2025 $ 3,000 $ 12 $ 2,988 April 9, 2020 3.750% Senior Secured Notes due 2027 4,000 17 3,983 April 9, 2020 3.875% Senior Secured Notes due 2030 7,000 78 6,922 April 9, 2020 4.375% Senior Secured Notes due 2040 2,000 47 1,953 April 9, 2020 4.500% Senior Secured Notes due 2050 3,000 24 2,976 April 9, 2020 1.500% Senior Secured Notes due 2026 1,000 5 995 June 24, 2020 2.050% Senior Secured Notes due 2028 1,250 8 1,242 June 24, 2020 2.550% Senior Secured Notes due 2031 1,750 12 1,738 June 24, 2020 Total of Senior Secured Notes issued 23,000 203 22,797 Secured bridge loan facility due 2021 19,000 257 18,743 April 1, 2020 Secured term loan facility due 2027 4,000 107 3,893 April 1, 2020 Total of Secured loan facilities issued 23,000 364 22,636 Total Issuances and Borrowings $ 46,000 $ 567 $ 45,433 Commitment Letters In connection with the entry into the Business Combination Agreement, T-Mobile USA entered into the Commitment Letter, with certain financial institutions named therein that committed to provide up to $27.0 billion in secured debt financing through May 1, 2020, including a $4.0 billion secured revolving credit facility, a $4.0 billion secured term loan facility, and a $19.0 billion secured bridge loan facility. The funding of the debt facilities provided for in the Commitment Letter was subject to the satisfaction of the conditions set forth therein, including consummation of the Merger. On April 1, 2020, in connection with the closing of the Merger, T-Mobile USA and certain of its affiliates, as guarantors, entered into a Bridge Loan Credit Agreement with certain financial institutions named therein, providing for a $19.0 billion secured bridge loan facility (“New Secured Bridge Loan Facility”). The New Secured Bridge Loan Facility bears interest at a rate equal to a per annum rate of LIBOR plus a margin of 1.25% and matures on March 31, 2021. On April 1, 2020, in connection with the closing of the Merger, T-Mobile USA and certain of its affiliates, as guarantors, entered into a Credit Agreement (the “New Credit Agreement”) with certain financial institutions named therein, providing for a $4.0 billion secured term loan facility (“New Secured Term Loan Facility”) and a $4.0 billion revolving credit facility (“New Revolving Credit Facility”). On September 16, 2020, we increased the aggregate commitment under the New Revolving Credit Facility to $5.5 billion through an amendment (the “Incremental Amendment”) to the New Credit Agreement. The New Secured Term Loan Facility bears interest at a rate equal to a per annum rate of LIBOR plus a margin of 3.00% and matures on April 1, 2027. The New Revolving Credit Facility bears interest at a rate equal to a per annum rate of LIBOR plus a margin of 1.25% with the margin subject to a reduction to 1.00% if T-Mobile’s Total First Lien Net Leverage Ratio (as defined in the New Credit Agreement) is less than or equal to 0.75 to 1.00. The commitments under the New Revolving Credit Facility mature on April 1, 2025. The New Credit Agreement contains customary representations, warranties and covenants, including a financial maintenance covenant of 3.3x with respect to T-Mobile’s Total First Lien Net Leverage Ratio commencing with the period ending September 30, 2020 and excess cash flow prepayment requirements commencing with the fiscal year ending December 31, 2021. On April 1, 2020, in connection with the closing of the Merger, we drew down on our $19.0 billion New Secured Bridge Loan Facility and our $4.0 billion New Secured Term Loan Facility. We used the net proceeds of $22.6 billion from the draw down of the secured facilities to repay our $4.0 billion Incremental Term Loan Facility with DT and to repurchase from DT $4.0 billion of indebtedness to affiliates, consisting of $2.0 billion of 5.300% Senior Notes due 2021 and $2.0 billion of 6.000% Senior Notes due 2024, as well as to redeem certain debt of Sprint and Sprint’s subsidiaries, including the secured term loans due 2024 with a total principal amount outstanding of $5.9 billion, accounts receivable facility with a total amount outstanding of $2.3 billion, and Sprint’s 7.250% Guaranteed Notes due 2028 with a total principal amount outstanding of $1.0 billion, and for post-closing general corporate purposes of the combined company. In connection with the financing provided for in the Commitment Letter, we incurred certain fees payable to the financial institutions, including certain financing fees on the secured term loan commitment and fees for structuring, funding, and providing the commitments. On April 1, 2020, in connection with the closing of the Merger, we paid $355 million in Commitment Letter fees to certain financial institutions. Senior Secured Notes On April 9, 2020, T-Mobile USA and certain of its affiliates, as guarantors, issued an aggregate of $19.0 billion in Senior Secured Notes bearing interest rates ranging from 3.500% to 4.500% and maturing in 2025 through 2050, and used the net proceeds of $18.8 billion together with cash on hand to repay all of the outstanding amounts under, and terminate, our $19.0 billion New Secured Bridge Loan Facility, as described above. On June 24, 2020, T-Mobile USA and certain of its affiliates, as guarantors, issued an aggregate of $4.0 billion in Senior Secured Notes bearing interest rates ranging from 1.500% to 2.550% and maturing in 2026 through 2031. The Senior Secured Notes were issued for refinancing callable Senior Notes and, subsequent to the issuance, we redeemed certain Senior Notes as set forth below under “Senior Secured Notes – Redemptions and Repayments” and “Senior Notes to Affiliates.” Subsequent to September 30, 2020, on October 6, 2020, T-Mobile USA issued $500 million of 2.050% Senior Secured Notes due 2028, $750 million of 2.550% Senior Secured Notes due 2031, $1.25 billion of 3.000% Senior Secured Notes due 2041, and $1.5 billion of 3.300% Senior Secured Notes due 2051. On October 9, 2020, we used the net proceeds of $4.0 billion to repay at par all of the outstanding amounts under, and terminate, our New Secured Term Loan Facility. Subsequent to September 30, 2020, on October 28, 2020, T-Mobile USA issued $1.0 billion of 2.250% Senior Secured Notes due 2031, $1.25 billion of 3.000% Senior Secured Notes due 2041, $1.5 billion of 3.300% Senior Secured Notes due 2051 and $1.0 billion of 3.600% Senior Secured Notes due 2060. We intend to use the net proceeds of $4.6 billion for general corporate purposes, which may include among other things, acquisitions of additional spectrum and refinancing existing indebtedness on an ongoing basis. Subsequent to September 30, 2020, on October 30, 2020, we entered into a $5.0 billion senior secured term loan commitment with certain financial institutions. Up to $5.0 billion of loans under the commitment may be drawn at any time (subject to customary conditions precedent) through June 30, 2021. If drawn, the facility matures in 364 days with one six-month extension exercisable at our discretion. Proceeds may be used for general corporate purposes and will accrue interest at a rate of LIBOR plus a margin of 1.25% per annum. Debt Assumed In connection with the Merger, we assumed the following indebtedness of Sprint: (in millions) Fair value as of April 1, 2020 Principal Outstanding as of September 30, 2020 Carrying Value as of September 30, 2020 7.250% Senior Notes due 2021 $ 2,324 $ 2,250 $ 2,300 7.875% Senior Notes due 2023 4,682 4,250 4,624 7.125% Senior Notes due 2024 2,746 2,500 2,720 7.625% Senior Notes due 2025 1,677 1,500 1,661 7.625% Senior Notes due 2026 1,701 1,500 1,687 3.360% Senior Secured Series 2016-1 A-1 Notes due 2021 (1) 1,310 875 874 4.738% Senior Secured Series 2018-1 A-1 Notes due 2025 (1) 2,153 2,100 2,148 5.152% Senior Secured Series 2018-1 A-2 Notes due 2028 (1) 1,960 1,838 1,953 7.000% Senior Notes due 2020 1,510 — — 11.500% Senior Notes due 2021 1,105 1,000 1,074 6.000% Senior Notes due 2022 2,372 2,280 2,355 6.875% Senior Notes due 2028 2,834 2,475 2,817 8.750% Senior Notes due 2032 2,649 2,000 2,630 Accounts receivable facility 2,310 — — Other debt 464 336 312 Total Debt Assumed $ 31,797 $ 24,904 $ 27,155 (1) In connection with the closing of the Merger, we assumed Sprint’s spectrum-backed notes which are collateralized by the acquired directly held and third-party leased Spectrum licenses. See “Spectrum Financing” section below for further information. Redemptions and Repayments During the nine months ended September 30, 2020, we repaid the following loan facilities and redeemed the following Senior Notes held by third parties and Senior Notes held by affiliates: (in millions) Principal Amount Write-off of Premiums and Issuance Costs (1) Other (2) Redemption or Repayment Date Redemption Price Secured bridge loan facility due 2021 $ 19,000 $ 251 $ (47) April 9, 2020 100.128 % 6.500% Senior Notes due 2024 1,000 12 22 July 4, 2020 102.167 % 6.375% Senior Notes due 2025 1,700 24 36 September 1, 2020 102.125 % Total of Secured bridge loan facility and Senior Notes to third parties redeemed 21,700 287 11 5.300% Senior Notes to affiliates due 2021 (3) 2,000 — — April 1, 2020 100.000 % 6.000% Senior Notes to affiliates due 2024 (3) 1,350 (26) — April 1, 2020 100.000 % 6.000% Senior Notes to affiliates due 2024 (3) 650 (15) — April 1, 2020 100.000 % Incremental term loan facility to affiliates due 2022 2,000 — — April 1, 2020 100.000 % Incremental term loan facility to affiliates due 2024 2,000 — — April 1, 2020 100.000 % 5.125% Senior Secured Notes to affiliates due 2021 1,250 15 — July 4, 2020 100.000 % Total of Senior Notes and Incremental term loan facilities to affiliates redeemed 9,250 (26) — Total Redemptions $ 30,950 $ 261 $ 11 Accounts receivable facility $ 2,310 $ — $ — April 1, 2020 100.00 % 3.360% Senior Secured Series 2016-1 A-1 Notes due 2021 438 — — Various N/A 7.000% Senior Notes due 2020 1,500 — — August 15, 2020 N/A Secured term loan facility due 2027 10 — — September 29, 2020 N/A Other debt 407 — — Various N/A Total Repayments $ 4,665 $ — $ — (1) Write-off of premiums, discounts and issuance costs are included in Other expense, net in our Condensed Consolidated Statements of Comprehensive Income. Write-off of issuance costs are included in Loss on redemption of debt within Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows. (2) Primarily represents a reimbursement of a portion of the commitment letter fees that were paid to financial institutions when we drew down on the Secured Bridge Loan Facility on April 1, 2020 and is included in Other expense, net in our Condensed Consolidated Statements of Comprehensive Income. (3) Pursuant to the Financing Matters Agreement, the Senior Notes were effectively redeemed through a repurchase and were cancelled and retired in full on April 1, 2020. On April 9, 2020, we repaid all of the outstanding amounts under, and terminated, our $19.0 billion New Secured Bridge Loan Facility. Additionally, in connection with the repayment of our New Secured Bridge Loan Facility, we received a reimbursement of $71 million, which represents a portion of the Commitment Letter fees that were paid to certain financial institutions when we drew down on the New Secured Bridge Loan Facility on April 1, 2020. The reimbursement is presented in Other (expense) income, net in our Condensed Consolidated Statements of Comprehensive Income. On July 4, 2020, we redeemed $1.0 billion aggregate principal amount of our 6.500% Senior Notes due 2024. The notes were redeemed at a redemption price equal to 102.167% of the principal amount of the notes (plus accrued and unpaid interest thereon), and were paid on July 6, 2020. The redemption premium was approximately $22 million and the write off of issuance costs and consent fees was approximately $12 million, which were included in Other (expense) income, net in our Condensed Consolidated Statements of Comprehensive Income and Losses on redemption of debt in our Condensed Consolidated Statements of Cash Flows. On August 15, 2020, we repaid at maturity $1.5 billion aggregate principal amount of our 7.000% Senior Notes due 2020 (plus accrued and unpaid interest thereon). On September 1, 2020, we redeemed $1.7 billion aggregate principal amount of our 6.375% Senior Notes due 2025. The notes were redeemed at a redemption price equal to 102.125% of the principal amount of the notes (plus accrued and unpaid interest thereon), and were paid on September 1, 2020. The redemption premium was approximately $36 million and the write off of issuance costs and consent fees was approximately $24 million, which were included in Other (expense) income, net in our Condensed Consolidated Statements of Comprehensive Income. Subsequent to September 30, 2020, on October 9, 2020, we repaid at par all of the outstanding amounts under, and terminated, our New Secured Term Loan Facility. On July 4, 2020, we also redeemed $1.25 billion aggregate principal amount of our 5.125% Senior Notes to affiliates due 2021, as further described below under “Senior Notes to Affiliates.” Financing Matters Agreement Pursuant to the Financing Matters Agreement, DT agreed, among other things, to consent to the incurrence by T-Mobile USA of secured debt in connection with and after the consummation of the Merger, and to provide a lock up on sales thereby as to certain Senior Notes of T-Mobile USA held thereby. In connection with receiving the requisite consents, we made upfront payments to DT of $7 million during the second quarter of 2018. These payments were recognized as a reduction to Long-term debt to affiliates in our Condensed Consolidated Balance Sheets. On April 1, 2020, in connection with the closing of the Merger, we: • Repaid our $4.0 billion Incremental Term Loan Facility with DT, consisting of a $2.0 billion Incremental Term Loan Facility due 2022 and a $2.0 billion Incremental Term Loan Facility due 2024; • Terminated our revolving credit facility; • Repurchased from DT $4.0 billion of indebtedness to affiliates, consisting of $2.0 billion of 5.300% Senior Notes due 2021 and $2.0 billion of 6.000% Senior Notes due 2024; • Amended the $1.25 billion of 5.125% Senior Notes due 2025 and $1.25 billion of 5.375% Senior Notes due 2027, which represent indebtedness to affiliates, to change the maturity dates thereof to April 15, 2021 and April 15, 2022, respectively (the “2025 and 2027 Amendments”); and • Made an additional payment for requisite consents to DT of $13 million. These payments were recognized as a reduction to Long-term debt to affiliates in our Condensed Consolidated Balance Sheets. In accordance with the consents received from DT, on December 20, 2018, T-Mobile USA, the guarantors and Deutsche Bank Trust Company Americas, as trustee, executed and delivered the 38 th supplemental indenture to the Indenture, pursuant to which, with respect to certain T-Mobile USA Senior Notes held by DT, the Debt Amendments (as defined below under “Consents on Debt to Third Parties”) and the 2025 and 2027 Amendments became effective immediately prior to the consummation of the Merger. Senior Notes to Affiliates On July 4, 2020, we redeemed $1.25 billion aggregate principal amount of our 5.125% Senior Notes to affiliates due 2021. The notes were redeemed at a redemption price equal to 100.00% of the principal amount of the notes (plus accrued and unpaid interest thereon), and were paid on July 6, 2020. The write off of discounts was approximately $15 million and was included in Other (expense) income, net in our Condensed Consolidated Statements of Comprehensive Income and Losses on redemption of debt in our Condensed Consolidated Statements of Cash Flows. Consents on Debt to Third Parties On May 18, 2018, under the terms and conditions described in the Consent Solicitation Statement, we obtained consents necessary to effect certain amendments to our Senior Notes to third parties in connection with the Business Combination Agreement. Pursuant to the Consent Solicitation Statement, third-party note holders agreed, among other things, to consent to increasing the amount of Secured Indebtedness under Credit Facilities that can be incurred from the greater of $9.0 billion and 150% of Consolidated Cash Flow to the greater of $9.0 billion and an amount that would not cause the Secured Debt to Cash Flow Ratio (calculated net of cash and cash equivalents) to exceed 2.00x (the “Ratio Secured Debt Amendments”) and in each case as such capitalized term is defined in the Indenture. In connection with receiving the requisite consents for the Ratio Secured Debt Amendments, we made upfront payments to third-party note holders of $17 million during the second quarter of 2018. These payments were recognized as a reduction to Long-term debt in our Condensed Consolidated Balance Sheets. These upfront payments increased the effective interest rate of the related debt. In addition, note holders agreed, among other things, to allow certain entities related to Sprint’s existing spectrum securitization notes program (“Existing Sprint Spectrum Program”) to be non-guarantor Restricted Subsidiaries, provided that the principal amount of the spectrum notes issued and outstanding under the Existing Sprint Spectrum Program does not exceed $7.0 billion and that the principal amount of such spectrum notes reduces the amount available under the Credit Facilities ratio basket, and to revise the definition of GAAP to mean generally accepted accounting principles in effect from time to time, unless the Company elects to “freeze” GAAP as of any date, and to exclude the effect of the changes in the accounting treatment of lease obligations (the “Existing Sprint Spectrum and GAAP Amendments,” and together with the Ratio Secured Debt Amendments, the “Debt Amendments”). In connection with receiving the requisite consents for the Existing Sprint Spectrum and GAAP Amendments, we made upfront payments to third-party note holders of $14 million during the second quarter of 2018. These payments were recognized as a reduction to Long-term debt in our Condensed Consolidated Balance Sheets. These upfront payments increased the effective interest rate of the related debt. In connection with obtaining the requisite consents, on May 20, 2018, T-Mobile USA, the guarantors and Deutsche Bank Trust Company Americas, as trustee, executed and delivered the 37 th supplemental indenture to the Indenture, pursuant to which, with respect to each of the Notes, the Debt Amendments would become effective immediately prior to the consummation of the Merger. We paid third-party bank fees associated with obtaining the requisite consents related to the Debt Amendments of $6 million during the second quarter of 2018, which we recognized as Selling, general and administrative expenses in our Condensed Consolidated Statements of Comprehensive Income. On April 1, 2020, in connection with the closing of the Merger, we made additional payments to third-party note holders for requisite consents related to the Ratio Secured Debt Amendments of $54 million and related to the Existing Sprint Spectrum and GAAP Amendments of $41 million. These payments were recognized as a reduction to Long-term debt in our Condensed Consolidated Balance Sheets. These payments increased the effective interest rate of the related debt. Spectrum Financing On April 1, 2020, in connection with the closing of the Merger, we assumed Sprint’s spectrum-backed notes which are collateralized by the acquired directly held and third-party leased Spectrum licenses (collectively, the “Spectrum Portfolio“) transferred to wholly owned bankruptcy-remote special purpose entities (collectively, the “Spectrum Financing SPEs”). As of September 30, 2020, the total outstanding obligations under these Notes was $4.8 billion. In October 2016, certain subsidiaries of Sprint Communications, Inc. transferred the Spectrum Portfolio to the Spectrum Financing SPEs, which was used as collateral to raise an initial $3.5 billion in senior secured notes (the “2016 Spectrum-Backed Notes”) bearing interest at 3.360% per annum under a $7.0 billion securitization program. The 2016 Spectrum-Backed Notes are repayable over a five-year term, with interest-only payments over the first four quarters and amortizing quarterly principal payments thereafter commencing December 2017 through September 2021. During the nine months ended September 30, 2020, we made scheduled principal repayments of $438 million, resulting in a total principal amount outstanding related to the 2016 Spectrum-Backed Notes of $875 million as of September 30, 2020, which was classified as Short-term debt in the Condensed Consolidated Balance Sheets . In March 2018, Sprint issued approximately $3.9 billion in aggregate principal amount of senior secured notes (the “2018 Spectrum-Backed Notes” and together with the 2016 Spectrum-Backed Notes, the “Spectrum-Backed Notes”) under the existing $7.0 billion securitization program, consisting of two series of senior secured notes. The first series of notes totaled $2.1 billion in aggregate principal amount, bears interest at 4.738% per annum, and has quarterly interest-only payments until June 2021, and amortizing quarterly principal amounts thereafter commencing in June 2021 through March 2025. As of September 30, 2020, $263 million of the aggregate principal amount was classified as Short-term debt in the Condensed Consolidated Balance Sheets. The second series of notes totaled approximately $1.8 billion in aggregate principal amount, bears interest at 5.152% per annum, and has quarterly interest-only payments until June 2023, and amortizing quarterly principal amounts thereafter commencing in June 2023 through March 2028. The Spectrum Portfolio, which also serves as collateral for the Spectrum-Backed Notes, remains substantially identical to the original portfolio from October 2016. Simultaneously with the October 2016 offering, Sprint Communications, Inc. entered a long-term lease with the Spectrum Financing SPEs for the ongoing use of the Spectrum Portfolio. Sprint Communications, Inc. is required to make monthly lease payments to the Spectrum Financing SPEs in an aggregate amount that is market-based relative to the spectrum usage rights as of the closing date and equal to $165 million per month. The lease payments, which are guaranteed by T-Mobile subsidiaries, are sufficient to service all outstanding series of the 2016 Spectrum Backed Notes and the lease also constitutes collateral for the senior secured notes. Because the Spectrum Financing SPEs are wholly owned T-Mobile US subsidiaries, these entities are consolidated and all intercompany activity has been eliminated. Each Spectrum Financing SPE is a separate legal entity with its own separate creditors who will be entitled, prior to and upon the liquidation of the respective Spectrum Financing SPE, to be satisfied out of the Spectrum Financing SPE’s assets prior to any assets of such Spectrum Financing SPE becoming available to T-Mobile. Accordingly, the assets of each Spectrum Financing SPE are not available to satisfy the debts and other obligations owed to other creditors of T-Mobile until the obligations of such Spectrum Financing SPE under the spectrum-backed senior secured notes are paid in full. Certain provisions of the Spectrum Financing facility require us to maintain specified cash collateral balances. Amounts associated with these balances are considered to be restricted cash. Restricted Cash Certain provisions of our debt agreements require us to maintain specified cash collateral balances. Amounts associated with these balances are considered to be restricted cash. Standby Letters of Credit

Tower Obligations

Tower Obligations	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Tower Obligations	Note 9 – Tower Obligations Existing CCI Tower Lease Arrangements In 2012, we conveyed to CCI the exclusive right to manage and operate approximately 7,100 tower sites (“CCI Lease Sites”) via a master prepaid lease with site lease terms ranging from 23 to 37 years (the “2012 Tower Transaction”). CCI has fixed-price purchase options for the CCI Lease Sites totaling approximately $2.0 billion, exercisable at the end of the lease term. We lease back space at certain tower sites for an initial term of ten years, followed by optional renewals at customary terms. Assets and liabilities associated with the operation of the tower sites were transferred to special purpose entities (“SPEs”). Assets included ground lease agreements or deeds for the land on which the towers are situated, the towers themselves and existing subleasing agreements with other mobile network operator tenants that lease space at the tower sites. Liabilities included the obligation to pay ground lease rentals, property taxes and other executory costs. Upon closing of the 2012 Tower Transaction, CCI acquired an option to acquire the CCI Lease Sites at the end of their respective lease terms and entered into a master lease agreement under which we agreed to lease back space at certain of the tower sites. We determined the SPEs containing the CCI Lease Sites (“Lease Site SPEs”) are VIEs as they lack sufficient equity to finance their activities. We have a variable interest in the Lease Site VIE but are not the primary beneficiary as we lack the power to direct the activities that most significantly impact the Lease Site VIE’s economic performance. These activities include managing tenants and underlying ground leases, performing repair and maintenance on the towers, the obligation to absorb expected losses and the right to receive the expected future residual returns from the purchase option to acquire the CCI Lease Sites. As we determined that we are not the primary beneficiary and do not have a controlling financial interest in the Lease Site SPEs, the balances and operating results of the Lease Site SPEs are not included in our condensed consolidated financial statements. Due to our continuing involvement with the tower sites, we previously determined that we were precluded from applying sale-leaseback accounting. We recorded long-term financial obligations in the amount of the net proceeds received and recognized interest on the tower obligations at a rate of approximately 8% using the effective interest method. The tower obligations are increased by interest expense and amortized through contractual leaseback payments made by us to CCI and through net cash flows generated and retained by CCI from operation of the tower sites. The principal payments on the tower obligations are included in Other, net within Net cash (used in) provided by financing activities in our Condensed Consolidated Statements of Cash Flows. Our historical tower site asset costs are reported in Property and equipment, net in our Condensed Consolidated Balance Sheets and are depreciated. Upon adoption of the lease accounting guidance (ASC 842), we were required to reassess the previously failed sale-leasebacks and determine whether the transfer of the assets to the tower operator under the arrangement met the transfer of control criteria in the revenue standard and whether a sale should be recognized. We concluded that a sale has not occurred for the CCI Lease Sites and these sites continue to be accounted for as a failed sale-leaseback. Acquired CCI Tower Lease Arrangements Prior to the Merger, Sprint entered into a lease-out and leaseback arrangement with Global Signal Inc., a third party that was subsequently acquired by CCI, whereby the third party would lease (“Master Lease Sites”) or otherwise manage (“Managed Sites”) approximately 6,400 cell sites which included the towers and related assets. These agreements were assumed upon the close of the Merger, at which point the remaining term of the lease-out was approximately 17 years with no renewal options. T-Mobile leases back space on certain of these towers. CCI has a fixed-price purchase option for all (but not less than all) of the leased or subleased sites for approximately $2.3 billion, exercisable one year prior to the expiration of the agreement and ending 120 days prior to the expiration of the agreement. As of Merger close date, we recognized Property and equipment with a preliminary fair value of $1.5 billion and tower obligations related to amounts owed to CCI under the leaseback of $1.1 billion as the transfer of control criteria in the revenue standard for the tower assets was not met. We are in the process of finalizing the valuation of the assets acquired and liabilities assumed in the Merger, including income tax related amounts. Therefore, the preliminary fair values are subject to further adjustment as additional information is obtained and the valuations are completed. During the three months ended September 30, 2020, we recognized interest expense on the tower obligations at a rate of approximately 6% using the effective interest method. The tower obligations are increased by interest expense and amortized through contractual leaseback payments made by us to CCI. The principal payments on the tower obligations are included in Other, net within Net cash (used in) provided by financing activities in our Condensed Consolidated Statements of Cash Flows. The tower assets are reported in Property and equipment, net in our Condensed Consolidated Balance Sheets and are depreciated to their estimated residual values over the current leaseback periods, for which the weighted average remaining term was six years as of September 30, 2020. The following table summarizes the balances associated with both of the tower arrangements in the Condensed Consolidated Balance Sheets: (in millions) September 30, 2020 December 31, 2019 Property and equipment, net $ 1,544 $ 198 Tower obligations 3,079 2,236 Future minimum payments related to the tower obligations are approximately $393 million for the year ending September 30, 2021, $738 million in total for the years ending September 30, 2022 and 2023, $591 million in total for years ending September 30, 2024 and 2025, and $694 million in total for years thereafter. We are contingently liable for future ground lease payments through the remaining term of the CCI Lease Sites and the Master Lease Sites. These contingent obligations are not included in Operating lease liabilities as any amount due is contractually owed by CCI based on the subleasing arrangement. Under the arrangement, we remain primarily liable for ground lease payments on approximately 900 Managed Sites and have included lease liabilities of $285 million in our Operating lease liabilities as of September 30, 2020.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Note 10 – Revenue from Contracts with Customers Disaggregation of Revenue We provide wireless communications services to three primary categories of customers: • Postpaid customers generally include customers who are qualified to pay after receiving wireless communications services utilizing phones, wearables, DIGITS, or other connected devices which includes tablets and SyncUP products. Our postpaid customers include customers of T-Mobile and Sprint; • Prepaid customers generally include customers who pay for wireless communications services in advance. Our prepaid customers include customers of T-Mobile and Metro by T-Mobile; and • Wholesale customers include Machine-to-Machine and Mobile Virtual Network Operator customers that operate on our network but are managed by wholesale partners. Postpaid service revenues, including postpaid phone revenues and postpaid other revenues, were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Postpaid service revenues Postpaid phone revenues $ 9,532 $ 5,400 $ 24,450 $ 15,870 Postpaid other revenues 677 346 1,605 982 Total postpaid service revenues $ 10,209 $ 5,746 $ 26,055 $ 16,852 We operate as a single operating segment. The balances presented within each revenue line item in our Condensed Consolidated Statements of Comprehensive Income represent categories of revenue from contracts with customers disaggregated by type of product and service. Service revenues also include revenues earned for providing value added services to customers, such as handset insurance services. Revenue generated from the lease of mobile communication devices is included within Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income. We provide wireline communication services to domestic and international customers. Wireline service revenues of $213 million and $424 million for the three and nine months ended September 30, 2020, respectively, relate to the wireline operations acquired in the Merger and are presented in Roaming and other service revenues in our Condensed Consolidated Statements of Comprehensive Income. Equipment revenues from the lease of mobile communication devices were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Equipment revenues from the lease of mobile communication devices $ 1,350 $ 142 $ 2,936 $ 446 Contract Balances The opening and closing balances of our contract asset and contract liability balances from contracts with customers as of December 31, 2019 and September 30, 2020, were as follows: (in millions) Contract Assets Contract Liabilities Balance as of December 31, 2019 $ 63 $ 560 Balance as of September 30, 2020 243 783 Change $ 180 $ 223 Contract assets primarily represent revenue recognized for equipment sales with promotional bill credits offered to customers that are paid over time and are contingent on the customer maintaining a service contract. Through the Merger, we acquired contracts assets associated with promotional bill credits and subsidized devices with a value of $154 million as of April 1, 2020. The change in the existing and acquired contract asset balance includes customer activity related to new promotions, offset by billings on existing contracts and impairment which is recognized as bad debt expense. The current portion of our Contract assets of approximately $187 million and $50 million as of September 30, 2020 and December 31, 2019, respectively, was included in Other current assets in our Condensed Consolidated Balance Sheets. Contract liabilities are recorded when fees are collected, or we have an unconditional right to consideration (a receivable) in advance of delivery of goods or services. Through the Merger, we assumed contract liabilities with a value of $252 million as of April 1, 2020. Additional changes in contract liabilities are primarily related to the volume and rate plans of active prepaid subscribers. Contract liabilities are primarily included in Deferred revenue in our Condensed Consolidated Balance Sheets. Revenues for the three and nine months ended September 30, 2020 and 2019, include the following: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Amounts included in the beginning of year contract liability balance $ 5 $ 39 $ 543 $ 642 Remaining Performance Obligations As of September 30, 2020, the aggregate amount of transaction price allocated to remaining service performance obligations for postpaid contracts with subsidized devices and promotional bill credits that result in an extended service contract is $1.3 billion. We expect to recognize revenue as service is provided on these postpaid contracts over an extended contract term of 24 months. Transaction price allocated to remaining service performance obligations associated with subsidized devices and promotional bill credits acquired through the Merger at April 1, 2020, was $1.0 billion. Through the Merger, on April 1, 2020, we acquired contracts associated with lease promotional credits with aggregate amount of transaction price allocated to remaining service and lease performance obligations of $4.8 billion and $2.6 billion, respectively. As of September 30, 2020, the aggregate amount of transaction price allocated to remaining service and lease performance obligations associated with operating leases was $3.3 billion and $1.8 billion, respectively. We expect to recognize this revenue as service is provided over the lease contract term of 18 months. Information about remaining performance obligations that are part of a contract that has an original expected duration of one year or less have been excluded from the above, which primarily consists of monthly service contracts. Certain of our wholesale, roaming and other service contracts include variable consideration based on usage. This variable consideration has been excluded from the disclosure of remaining performance obligations. As of September 30, 2020, the aggregate amount of the contractual minimum consideration for wholesale, roaming and other service contracts is $382 million, $1.3 billion and $1.4 billion for 2020, 2021, and 2022 and beyond, respectively. These contracts have a remaining duration ranging from less than one year to nine years. Contract Costs The total balance of deferred incremental costs to obtain contracts was $1.0 billion and $906 million as of September 30, 2020 and December 31, 2019, respectively. Deferred contract costs incurred to obtain postpaid service contracts are amortized over a period of 24 months. The amortization period is monitored to reflect any significant change in assumptions. Amortization of deferred contract costs is included in Selling, general and administrative expenses in our Condensed Consolidated Statements of Comprehensive Income and was $221 million and $162 million for the three months ended September 30, 2020 and 2019, respectively, and $631 million and $415 million for the nine months ended September 30, 2020 and 2019, respectively. Immediately preceding the close of the Merger, Sprint had deferred costs to obtain postpaid contracts of approximately $1.7 billion. This balance was adjusted to zero as part of our purchase price allocation. Contract costs capitalized for new postpaid contracts will accumulate in Other assets in our Condensed Consolidated Balance Sheets from the Merger close date. As a result, there will be a net benefit to Operating income in our Condensed Consolidated Statements of Comprehensive Income during the remainder of the year as capitalization of costs exceed amortization. As capitalized costs amortize into expense over time, the accretive benefit to Operating income anticipated for the remainder of the year is expected to moderate in 2021 and normalize in 2022. The deferred contract cost asset is assessed for impairment on a periodic basis. There were no impairment losses recognized on deferred contract cost assets for the three and nine months ended September 30, 2020 and 2019.

Employee Compensation and Benef

Employee Compensation and Benefit Plans	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Employee Compensation and Benefit Plans	Note 11 – Employee Compensation and Benefit Plans Under our 2013 Omnibus Incentive Plan (the “Incentive Plan”), we are authorized to issue up to 101 million shares of our common stock. Under the Incentive Plan, we can grant stock options, stock appreciation rights, restricted stock, restricted stock units (“RSUs”), and performance awards to eligible employees, consultants, advisors and non-employee directors. As of September 30, 2020, there were approximately 25 million shares of common stock available for future grants under the Incentive Plan. We grant RSUs to eligible employees, key executives and certain non-employee directors and performance-based restricted stock units (“PRSUs”) to eligible key executives. RSUs entitle the grantee to receive shares of our common stock upon vesting (with vesting generally occurring annually over a three-year period), subject to continued service through the applicable vesting date. PRSUs entitle the holder to receive shares of our common stock at the end of a performance period of generally up to three years if the applicable performance goals are achieved and generally subject to continued service through the applicable performance period. The number of shares ultimately received by the holder of PRSUs is dependent on our business performance against the specified performance goal(s) over a pre-established performance period. We also maintain an employee stock purchase plan (“ESPP”), under which eligible employees can purchase our common stock at a discounted price. Stock-based compensation expense and related income tax benefits were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions, except shares, per share and contractual life amounts) 2020 2019 2020 2019 Stock-based compensation expense $ 161 $ 126 $ 558 $ 366 Income tax benefit related to stock-based compensation $ 34 $ 25 $ 105 $ 70 Weighted average fair value per stock award granted $ 114.52 $ 77.41 $ 97.28 $ 73.18 Unrecognized compensation expense $ 670 $ 631 $ 670 $ 631 Weighted average period to be recognized (years) 1.9 1.8 1.9 1.8 Fair value of stock awards vested $ 264 $ 14 $ 1,079 $ 356 Stock Awards On April 1, 2020, we closed the Merger to combine T-Mobile and Sprint pursuant to the Business Combination Agreement. Pursuant to the Business Combination Agreement, upon the completion of the Merger, T-Mobile assumed Sprint’s stock compensation plans. In addition, pursuant to the Business Combination Agreement, at the Effective Time, each outstanding option to purchase Sprint common stock (other than under Sprint’s Employee Stock Purchase Plan), each award of time-based RSUs in respect of shares of Sprint common stock and each award of performance-based RSUs in respect of shares of Sprint common stock, in each case, that was outstanding as of immediately prior to the Effective Time was automatically adjusted by the Exchange Ratio (as defined in the Business Combination Agreement) and converted into an equity award of the same type covering shares of T-Mobile common stock, on the same terms and conditions, (including, if applicable, any continuing vesting requirements (but excluding any performance-based vesting conditions)) under the applicable Sprint plan and award agreement in effect immediately prior to the Effective Time (the “Assumed Awards”). The applicable amount of performance-based RSUs eligible for conversion was based on formulas and approximated 100% of target. Any accrued but unpaid dividend equivalents with respect to any such award of time-based RSUs or performance-based RSUs were assumed by T-Mobile at the Effective Time and became an obligation with respect to the applicable award of RSUs in respect of shares of T-Mobile common stock. On April 22, 2020, we filed a Form S-8 to register a total of 25,304,224 shares of common stock, representing those covered by the Sprint Corporation 1997 Long-Term Stock Incentive Program, the Sprint Corporation 2007 Omnibus Incentive Plan and the Sprint Corporation Amended and Restated 2015 Omnibus Incentive Plan that T-Mobile assumed in connection with the closing of the Merg er. This included 7,043,843 shares of T-Mobile common stock issuable upon exercise or settlement of the Assumed Awards held by current directors, officers, employees and consultants of T-Mobile or its subsidiaries who were directors, officers, employees and consultants of Sprint or its subsidiaries immediately prior to the Effective Time, as well as (a) 12,420,945 shares of T-Mobile common stock that remain available for issuance under the 2015 Plan and (b) 5,839,436 additional shares of T-Mobile common stock subject to awards granted under the 2015 Plan that may become available for issuance under the 2015 Plan if any awards under the 2015 Plan are forfeited, lapse unexercised or are settled in cash. Time-Based Restricted Stock Units and Restricted Stock Awards (in millions, except shares, per share and contractual life amounts) Number of Units or Awards Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested, December 31, 2019 10,503,211 $ 67.31 0.9 $ 824 Assumed through acquisition 1,852,527 83.90 Granted 5,598,737 95.56 Vested (6,151,759) 69.74 Forfeited (861,098) 84.14 Nonvested, September 30, 2020 10,941,618 81.90 1.0 1,251 Performance-Based Restricted Stock Units and Restricted Stock Awards (in millions, except shares, per share and contractual life amounts) Number of Units or Awards Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested, December 31, 2019 3,803,539 $ 69.78 1.0 $ 300 Assumed through acquisition 3,535,384 83.90 Granted 1,962,547 105.49 Vested (5,120,598) 76.32 Forfeited (136,359) 83.90 Nonvested, September 30, 2020 4,044,513 83.69 0.9 465 PRSUs included in the table above are shown at target. Share payout can range from 0% to 200% based on different performance outcomes. Weighted average grant date fair value of RSU and PRSU assumed through acquisition is based on the fair value on the date assumed. Payment of the underlying shares in connection with the vesting of RSU awards generally triggers a tax obligation for the employee, which is required to be remitted to the relevant tax authorities. We have agreed to withhold shares of common stock otherwise issuable under the RSU awards to cover certain of these tax obligations, with the net shares issued to the employee accounted for as outstanding common stock. We withheld 648,872 and 53,349 shares of common stock to cover tax obligations associated with the payment of shares upon vesting of stock awards and remitted cash of $72 million and $4 million to the appropriate tax authorities for the three months ended September 30, 2020 and 2019, respectively. We withheld 3,703,906 and 1,474,011 shares of common stock to cover tax obligations associated with the payment of shares upon vesting of stock awards and remitted cash of $351 million and $108 million to the appropriate tax authorities for the nine months ended September 30, 2020 and 2019, respectively. Employee Stock Purchase Plan Our ESPP allows eligible employees to contribute up to 15% of their eligible earnings toward the semi-annual purchase of our shares of common stock at a discounted price, subject to an annual maximum dollar amount. Employees can purchase stock at a 15% discount applied to the closing stock price on the first or last day of the six-month offering period, whichever price is lower. The number of shares issued under our ESPP was 2,144,036 and 2,091,650 for the nine months ended September 30, 2020 and 2019, respectively. As of September 30, 2020, the number of securities remaining available for future sale and issuance under the ESPP was 4,253,858. Sprint’s ESPP was terminated prior to the Merger close and legacy Sprint employees were eligible to enroll in our ESPP on August 15, 2020. Our ESPP provides for an annual increase in the aggregate number of shares of our common stock reserved for sale and authorized for issuance thereunder as of the first day of each fiscal year (beginning with fiscal year 2016) equal to the lesser of (i) 5,000,000 shares of our common stock, and (ii) the number of shares of T-Mobile common stock determined by the Compensation Committee of the Board of Directors of the Company (the “Compensation Committee”). For fiscal years 2016 through 2019, the Compensation Committee determined that no such increase in shares of our common stock was necessary. However, an additional 5,000,000 shares of our common stock were automatically added to the ESPP share reserve as of January 1, 2020. Stock Options Stock options outstanding relate to the Metro Communications, Inc. 2010 Equity Incentive Compensation Plan, the Amended and Restated Metro Communications, Inc. 2004 Equity Incentive Compensation Plan, the Layer3 TV, Inc. 2013 Stock Plan, and the Sprint 2015 Plan (collectively, the “Stock Option Plans”). No new awards may be granted under the Stock Option Plans, and no awards were granted during the nine months ended September 30, 2020. The following activity occurred under the Stock Option Plans: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Outstanding at December 31, 2019 194,942 $ 13.80 2.9 Assumed through acquisition 1,635,518 33.37 Exercised (794,853) 52.27 Expired/canceled (4,296) 41.82 Outstanding at September 30, 2020 1,031,311 52.51 4.1 Exercisable at September 30, 2020 1,029,731 52.55 4.1 Weighted average grant date fair value of stock options assumed through acquisition is based on the fair value on the date assumed. Stock options exercised under the Stock Option Plans generated proceeds of approximately $27 million for the three months ended September 30, 2020 and $42 million and $1 million for the nine months ended September 30, 2020 and 2019, respectively. There were no proceeds for the three months ended September 30, 2019. The grant-date fair value of share-based incentive compensation awards attributable to post-combination services, including restricted stock units and stock options, from our Merger with Sprint was approximately $163 million. Pension Plan Upon the completion of our Merger with Sprint, we assumed the Pension Plan which provides defined benefits and other postretirement benefits to participants. The Pension Plan was amended in 2005 to freeze plan accruals for participants. The plan assets acquired and obligations assumed were recognized at fair value on the Merger close date. The components of net expense recognized for the Pension Plan were as follows: (in millions) Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Interest on projected benefit obligations $ 18 $ 35 Expected return on pension plan assets (15) (30) Net pension expense $ 3 $ 5 The net expense associated with the Pension Plan is included in Other (expense) income, net of our Condensed Consolidated Statements of Comprehensive Income. The fair value of our pension plan assets and certain other postretirement benefit plan assets in aggregate was $1.2 billion and our projected benefit obligations in aggregate was $2.1 billion as of both April 1, 2020 and September 30, 2020. As a result, the plans were underfunded by approximately $900 million as of both April 1, 2020 and September 30, 2020, and were recorded in Other long-term liabilities in our Condensed Consolidated Balance Sheets. During the three and nine months ended September 30, 2020, we made contributions of $26 million and $42 million, respectively, to the benefit plan. No contributions were made in fiscal periods prior to April 1, 2020. We expect to make contributions to the Plan of $16 million through the year ended December 31, 2020. Employee Retirement Savings Plan We sponsor retirement savings plans for the majority of our employees under Section 401(k) of the Internal Revenue Code and similar plans. The plans allow employees to contribute a portion of their pretax and post-tax income in accordance with specified guidelines. The plans provide that we match a percentage of employee contributions up to certain limits. Employer

Discontinued Operations and Dis

Discontinued Operations and Disposal Groups	9 Months Ended
	Sep. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Note 12 - Discontinued Operations On July 26, 2019, we entered into an Asset Purchase Agreement with Sprint and DISH. On June 17, 2020, T-Mobile, Sprint and DISH entered into the First Amendment. Pursuant to the First Amendment to the Asset Purchase Agreement, T-Mobile, Sprint and DISH agreed to proceed with the closing of the Prepaid Transaction in accordance with the Asset Purchase Agreement on July 1, 2020, subject to the terms and conditions of the Asset Purchase Agreement and the terms and conditions of the Consent Decree. On July 1, 2020, pursuant to the Asset Purchase Agreement, upon the terms and subject to the conditions thereof, we completed the Prepaid Transaction. Upon closing of the Prepaid Transaction, we received $1.4 billion from DISH for the Prepaid Business, subject to a working capital adjustment. The close of the Prepaid Transaction did not have a significant impact on our Condensed Consolidated Statements of Comprehensive Income. The assets of the Prepaid Business included EIP receivables originated pursuant to financed equipment purchases by customers of the Prepaid Business. At the time of the Prepaid Transaction, DISH did not hold certain licenses required to purchase or originate such contracts. In order to transfer the economics of the contracts to DISH without transferring ownership of them, the parties entered into a Participation Agreement under which we agreed to transfer a 100% participation interest in the contracts to DISH. Under the terms of the agreement, DISH retains all cash flows collected on these assets, and there is no recourse against us for any credit losses on such loans. The proceeds received from DISH in exchange for this participation interest was a component of total consideration received for the Prepaid Transaction. We will temporarily continue to originate equipment installment contracts on DISH’s behalf under the same terms in exchange for an amount equal to the initial outstanding principal balance of the originated contracts, again without recourse against us for any credit losses. Of the total $1.4 billion of proceeds received under the Prepaid Transaction, approximately $162 million was allocated to the EIP receivables to which we transferred DISH a 100% participation interest. We accounted for this portion of the proceeds as a secured borrowing and present it in Other, net, within Net cash (used in) provided by financing activities in our Condensed Consolidated Statements of Cash Flows accordingly. The remaining $1.2 billion was allocated to the divested net assets of the Prepaid Business. The net cash received for the Prepaid Business is presented in Proceeds from the divestiture of prepaid business within Net cash used in investing activities in our Condensed Consolidated Statements of Cash Flows. The results of the Prepaid Business include revenues and expenses directly attributable to the operations disposed. Corporate and administrative expenses not directly attributable to the operations were not allocated to the Prepaid Business. The results of the Prepaid Business from April 1, 2020, through September 30, 2020, are presented in Income from discontinued operations, net of tax in our Condensed Consolidated Statements of Comprehensive Income. The components of discontinued operations from the Merger close date of April 1, 2020, through September 30, 2020, were as follows: (in millions) Nine Months Ended September 30, 2020 Major classes of line items constituting pretax income from discontinued operations Prepaid revenues $ 973 Roaming and other service revenues 27 Total service revenues 1,000 Equipment revenues 270 Total revenues 1,270 Cost of services 25 Cost of equipment sales 499 Selling, general and administrative 314 Total operating expenses 838 Pretax income from discontinued operations 432 Income tax expense (112) Income from discontinued operations $ 320 Net cash provided by operating activities from the Prepaid Business included in the Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2020, were $611 million, all of which relates to the operations of the Prepaid Business during the three months ended June 30, 2020. There were no cash flows from investing or financing related to the Prepaid Business for the three and nine months ended September 30, 2020. Continuing Involvement Upon the closing of the Prepaid Transaction, we and DISH entered into (i) a License Purchase Agreement pursuant to which (a) DISH has the option to purchase certain 800 MHz spectrum licenses for a total of approximately $3.6 billion in a transaction to be completed, subject to certain additional closing conditions, following an application for FCC approval to be filed three years following the closing of the Merger and (b) we will have the option to lease back from DISH, as needed, a portion of the spectrum sold for an additional two years following the closing of the spectrum sale transaction, (ii) a Transition Services Agreement providing for our provisioning of transition services to DISH in connection with the Prepaid Business for a period of up to three years following the closing of the Prepaid Transaction, (iii) a Master Network Services Agreement providing for the provisioning of network services to customers of the Prepaid Business for a period of up to seven years following the closing of the Prepaid Transaction, and (iv) an Option to Acquire Tower and Retail Assets offering DISH the option to acquire certain decommissioned towers and retail locations from us, subject to obtaining all necessary third-party consents, for a period of up to five years following the closing of the Prepaid Transaction. In the event DISH breaches the License Purchase Agreement or fails to deliver the purchase price following the satisfaction or waiver of all closing conditions, DISH’s sole liability is to pay us a fee of approximately $72 million. Additionally, if DISH does not exercise the option to purchase the 800 MHz spectrum licenses, we have an obligation to offer the licenses for sale through an auction. If the specified minimum price of $3.6 billion was not met in the auction, we would retain the licenses. As the sale of 800 MHz spectrum licenses is not expected to close within one year, the criteria for presentation as an asset held for sale is not met. Cash flows associated with the Master Network Services Agreement and Transition Services Agreement are included within Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Note 13 – Income Taxes Within our Condensed Consolidated Statements of Comprehensive Income, we recorded Income tax expense on continuing operations of $407 million and $325 million for the three months ended September 30, 2020 and 2019, respectively, and $715 million and $921 million for the nine months ended September 30, 2020 and 2019, respectively. The change for the three months ended September 30, 2020 was primarily from higher income before income taxes. The change for the nine months ended September 30, 2020 was primarily from lower income before income taxes. The effective tax rate from continuing operations was 24.5% and 27.1% for the three months ended September 30, 2020 and 2019, respectively, and 26.4% and 25.3% for the nine months ended September 30, 2020 and 2019, respectively. The decrease in the effective income tax rate for the three months ended September 30, 2020 was primarily due to higher income before income taxes, an increase in excess tax benefits, and the benefit of a reduction in the valuation allowance against deferred tax assets related to federal tax credits for the three months ended September 30, 2020 compared to the three months ended September 30, 2019. The increase in the effective income tax rate for the nine months ended September 30, 2020, was primarily due to lower income before income taxes and an increase in expenses that are not deductible for income tax purposes, including our Layer3 goodwill impairment and certain Merger-related costs. As a result of the Merger, we acquired additional deferred tax assets for which a valuation allowance reserve is deemed to be necessary, as well as additional uncertain tax benefit reserves. The estimated amount of the valuation allowance reserve and uncertain tax benefit reserves was $1.0 billion and $540 million, respectively, as of September 30, 2020. Due to the size and complexity of the Merger, our estimate of these amounts is preliminary and is subject to finalization and adjustment, which could be material, during the measurement period of up to one year from the Merger close date. During the measurement period, we will adjust these amounts if new information is obtained about facts or circumstances that existed as of the acquisition date that, if known, would have changed these amounts. See Note 2 - Business Combination for further information.

SoftBank Equity Transaction

SoftBank Equity Transaction	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
SoftBank Equity Transaction	Note 14 - SoftBank Equity Transaction On June 22, 2020, we entered into a Master Framework Agreement (the “Master Framework Agreement”), by and among the Company, SoftBank, SoftBank Group Capital Ltd, a wholly owned subsidiary of SoftBank (“SBGC”), Delaware Project 4 L.L.C., a wholly owned subsidiary of SoftBank, Delaware Project 6 L.L.C., a wholly owned subsidiary of SoftBank, Claure Mobile LLC (“CM LLC”), DT, and T-Mobile Agent LLC, a wholly owned subsidiary of the Company. The Master Framework Agreement and related transactions were entered into to facilitate SoftBank’s monetization of a portion of our common stock held by SoftBank (the “SoftBank Monetization”). In connection with the Master Framework Agreement, DT waived the restriction on the transfer under its Proxy, Lock-Up and ROFR Agreement, dated April 1, 2020, with SoftBank (the “SoftBank Proxy Agreement”) with respect to approximately 198 million shares of our common stock held by SoftBank (the “Released Shares”). Upon the close of the Public Equity Offering (as defined below), we received a payment from SoftBank for $304 million for our role in facilitating the SoftBank Monetization. The payment received from SoftBank, net of tax, of $230 million was recorded as Additional paid-in capital in our Condensed Consolidated Balance Sheets and is presented as a reduction of Repurchases of common stock within Net cash (used in) provided by financing activities within our Condensed Consolidated Statements of Cash Flows . Under the terms of the Master Framework Agreement and the agreements contemplated thereby, SBGC sold the Released Shares to us, and we participated in the following transactions: Public Equity Offering On June 26, 2020, we completed a registered public offering of approximately 154.1 million shares of our common stock ( the “Public Equity Offering”) at a price of $103.00 per share. The net proceeds of the Public Equity Offering were used to repurchase an equal number of issued and outstanding shares of our common stock from SBGC, pursuant to a Share Repurchase Agreement, dated as of June 22, 2020 (the “Share Repurchase Agreement”), between us and SBGC. Mandatory Exchangeable Offering Concurrent with the Public Equity Offering, we sold approximately 19.4 million shares of our common stock to a third-party trust. The net proceeds from the sale of shares to the trust were used to repurchase an equal number of issued and outstanding shares of our common stock from SBGC. The trust issued mandatory exchangeable trust securities, which entitle holders to receive quarterly distributions from the trust and a final mandatory exchange price to be settled on June 1, 2023 (“Mandatory Exchangeable Offering”). The trust was required to use a portion of the net proceeds from the Mandatory Exchangeable Offering to purchase U.S. Treasury securities, to fund quarterly distributions on the mandatory exchangeable trust securities, and the holders of the mandatory exchangeable trust securities will be entitled to a final mandatory exchange amount on June 1, 2023 that will depend on the daily volume-weighted average price of shares of our common stock. The sale of shares through the Public Equity Offering and to the trust occurred simultaneously with the purchase of shares from SBGC. These simultaneous transactions did not result in a net change to our treasury shares or shares of common stock outstanding. As these transactions occurred with separate counterparties, the exchange of shares and cash are presented on a gross basis in our Condensed Consolidated Statement of Stockholders’ Equity and Condensed Consolidated Statements of Cash Flows, respectively. The shares sold are presented in Shares issued in secondary offering and the shares purchased from SBGC are presented in Shares repurchased from SoftBank within our Condensed Consolidated Statement of Stockholders’ Equity. The cash received from the sale of shares is presented in Issuance of common stock and the cash paid to purchase shares from SoftBank are presented in Repurchases of common stock within Net cash (used in) provided by financing activities within our Condensed Consolidated Statements of Cash Flows. The Company is not affiliated with the trust, will not retain any proceeds from the offering of the trust securities, and will have no ongoing interest, economic or otherwise, in the trust securities. Rights Offering The Master Framework Agreement provides for the issuance of registered, transferable subscription rights (the “Rights Offering”) resulting in the sale of 19,750,000 shares of our common stock to our stockholders (other than SoftBank, DT and Marcelo Claure and their respective affiliates, who agreed to waive their ability to exercise or transfer such rights). The subscription rights provided the stockholders the option to purchase one share of common stock for every 20 shares of common stock owned, at the same price per share as the common stock sold in the Public Equity Offering of $103.00 per share. The Rights Offering exercise period expired on July 27, 2020. On August 3, 2020, the Rights Offering closed, resulting in the sale of 19,750,000 shares of our common stock. The net proceeds from the Rights Offering were used to purchase an equal number of shares from SBGC pursuant to the Share Repurchase Agreement. Marcelo Claure The Master Framework Agreement provided for the purchase of 5.0 million shares of our common stock by Marcelo Claure, a member of our board of directors, from us at the same price per share as the common stock sold in the Public Equity Offering of $103.00 per share . Following receipt of the necessary regulatory approvals on July 16, 2020, t he sale of shares to Marcelo Claure occurred simultaneously with our purchase of an equivalent number of shares from SBGC at the same price per share pursuant to the Share Repurchase Agreement. Ownership Following the SoftBank Monetization As of September 30, 2020, DT and SoftBank held, directly or indirectly, approximately 43.4% , and 8.6%, respectively, of the outstanding T-Mobile common stock, with the remaining approximately 48.0% of the outstanding T-Mobile common stock held by other stockholders. The SoftBank Proxy Agreement remains in effect with respect to the remaining shares of our common stock held by SoftBank. In addition, on June 22, 2020, DT, CM LLC, and Marcelo Claure entered into a Proxy, Lock-Up and ROFR Agreement (the “Claure Proxy Agreement,” together with the SoftBank Proxy Agreement, the “Proxy Agreements”), pursuant to which any shares of our common stock acquired after June 22, 2020 by Mr. Claure or CM LLC, an entity controlled by Mr. Claure, other than shares acquired as a result of Mr. Claure’s role as a director or officer of the Company, will be voted in the manner as directed by DT. Accordingly, as a result of the Proxy Agreements, DT has voting control as of September 30, 2020 over approximately 52.4% of the outstanding T-Mobile common stock. In addition, as provided for in the Master Framework Agreement, DT also holds certain call options over approximately 101.5 million shares of our common stock held by SBGC. DT Call Option In exchange for DT consenting to the transfer of the Released Shares and as provided for in the Master Framework Agreement, DT received direct and indirect call options over up to approximately 101.5 million shares of our common stock held by SBGC. The arrangement provides DT with a fixed-price call option to purchase up to approximately 44.9 million shares at a price of $101.46 per share indirectly from SBGC through a back-to-back arrangement where (i) DT can purchase such shares from us (the “DT Fixed-Price Call Option”) and (ii) we will fulfill our obligations under the DT Fixed-Price Call Option by simultaneously purchasing the same number of shares on the same economic terms from SBGC (the “T-Mobile Fixed-Price Call Option”). In addition, DT has a floating-price call option to purchase up to approximately 56.6 million shares from SBGC directly (the “DT Floating Option”). The call options expire on June 22, 2024 (the “Expiration Time”). The back-to-back arrangement can be initiated by DT at any time prior to the Expiration Time. The DT Floating Option cannot be exercised until the earlier of (i) 30 days prior to the Expiration Time and (ii) the later of (x) the date the DT Fixed-Price Call Option and the T-Mobile Fixed-Price Call Option are exercised in full and (y) October 2, 2020. Our obligations to DT under the DT Fixed-Price Call Option are secured solely by our rights under the T-Mobile Fixed-Price Call Option and DT has no recourse against us other than enforcement of this security arrangement. The DT Fixed-Price Call Option and the T-Mobile Fixed-Price Call Option represent free-standing derivatives and are recorded at fair value and marked-to-market each period. The fair value of each call option was estimated at $1.0 billion as of September 30, 2020 using the income approach. The fair value measurements are based on significant inputs not observable in the market and, therefore, represent a Level 3 measurement as defined in ASC 820. The key assumptions in applying the income approach include estimated share-price volatility, which was based on historical market trends and expected future performance of T-Mobile, as well as the assessment of counterparty credit risk. The asset associated with the T-Mobile Fixed-Price Call Option is recorded within Other current assets in the Condensed Consolidated Balance Sheets, and the liability associated with the DT Fixed-Price Call Option is recorded within Other current liabilities in the Condensed Consolidated Balance Sheets. As the mark-to-market valuations of the T-Mobile Fixed-Price Call Option and the DT Fixed-Price Call Option move in equal and offsetting directions, there is no net impact on our Condensed Consolidated Statements of Comprehensive Income . Subsequent to September 30, 2020, on October 6, 2020, we assigned our rights under the T-Mobile Fixed-Price Call Option to DT and DT terminated its right to purchase shares from us under the DT Fixed-Price Call Option, resulting in derecognition of the related derivative asset and liability in equal and offsetting amounts such that there was no net impact to our Condensed Consolidated Statements of Comprehensive Income .

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Note 15 – Earnings Per Share The computation of basic and diluted earnings per share was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions, except shares and per share amounts) 2020 2019 2020 2019 Income from continuing operations $ 1,253 $ 870 $ 1,994 $ 2,717 Income from discontinued operations, net of tax — — 320 — Net income $ 1,253 $ 870 $ 2,314 $ 2,717 Weighted average shares outstanding - basic 1,238,450,665 854,578,241 1,111,511,964 853,391,370 Effect of dilutive securities: Outstanding stock options and unvested stock awards 11,348,075 8,112,510 10,528,564 9,463,284 Weighted average shares outstanding - diluted 1,249,798,740 862,690,751 1,122,040,528 862,854,654 Basic earnings per share: Continuing operations $ 1.01 $ 1.02 $ 1.79 $ 3.18 Discontinued operations — — 0.29 — Earnings per share - basic $ 1.01 $ 1.02 $ 2.08 $ 3.18 Diluted earnings per share: Continuing operations $ 1.00 $ 1.01 $ 1.78 $ 3.15 Discontinued operations — — 0.28 — Earnings per share - diluted $ 1.00 $ 1.01 $ 2.06 $ 3.15 Potentially dilutive securities: Outstanding stock options and unvested stock awards 54,485 241 30,469 30,314 SoftBank contingent consideration 48,751,557 — 32,738,272 — On April 1, 2020, in connection with the closing of the Merger, we amended and restated the Company’s certificate of incorporation in the form of the Fifth Amended and Restated Certificate of Incorporation (the “Restated Certificate”). Pursuant to the Restated Certificate, the authorized capital stock of T-Mobile consists of 2,000,000,000 shares of T-Mobile common stock and 100,000,000 shares of preferred stock, par value $0.00001 per share. As of September 30, 2020, we had authorized 100 million shares of preferred stock, with a par value of $0.00001 per share. There was no preferred stock outstanding as of September 30, 2020 and 2019. Potentially dilutive securities were not included in the computation of diluted earnings per share if to do so would have been anti-dilutive or if there was a loss from continuing operations for the period.

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	Note 16 - Leases Lessee We are a lessee for non-cancelable operating and financing leases for cell sites, switch sites, retail stores, network equipment and office facilities with contractual terms that generally extend through 2035. Additionally, we lease dark fiber through non-cancelable operating leases with contractual terms that generally extend through 2041. The majority of cell site leases have an initial non-cancelable term of five five two Through the Merger, we acquired leases of real property, including cell sites, switch sites, dark fiber, retail stores and office facilities and recorded lease liabilities and associated right-of-use assets based on the discounted lease payments. Lease terms that are favorable or unfavorable to market terms were recorded as an adjustment to lease right-of-use assets on our Condensed Consolidated Balance Sheets. Favorable and unfavorable leases are amortized on a straight-line basis over the associated remaining lease term. On September 14, 2020, T-Mobile and American Tower Corporation (“American Tower”) entered into a lease agreement (the “American Tower Lease Agreement”) that will enable us to lease American Tower towers through April 2035 . The American Tower Lease Agreement extended the term and modified the rental payments for approximately 20,729 American Tower towers currently leased by us. As a result of this modification, we remeasured the associated right-of-use assets and lease liabilities resulting in an increase of $11.0 billion to each on the effective date of the modification . The components of lease expense were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Operating lease expense $ 1,259 $ 657 $ 3,082 $ 1,893 Financing lease expense: Amortization of right-of-use assets 183 146 508 376 Interest on lease liabilities 20 21 60 61 Total financing lease expense 203 167 568 437 Variable lease expense 106 62 239 185 Total lease expense $ 1,568 $ 886 $ 3,889 $ 2,515 Information relating to the lease term and discount rate is as follows: September 30, 2020 Weighted Average Remaining Lease Term (Years) Operating leases 10 Financing leases 3 Weighted Average Discount Rate Operating leases 4.0 % Financing leases 3.5 % Maturities of lease liabilities as of September 30, 2020, were as follows: (in millions) Operating Leases Finance Leases Twelve Months Ending September 30, 2021 $ 4,717 $ 1,100 2022 4,361 792 2023 3,754 426 2024 3,301 89 2025 2,785 61 Thereafter 19,184 72 Total lease payments 38,102 2,540 Less: imputed interest 7,786 117 Total $ 30,316 $ 2,423 Interest payments for financing leases were $19 million and $20 million for the three months ended September 30, 2020 and 2019, respectively, and $59 million and $61 million for the nine months ended September 30, 2020 and 2019, respectively. As of September 30, 2020, we have additional operating leases for cell sites and commercial properties that have not yet commenced with future lease payments of approximately $283 million. As of September 30, 2020, we were contingently liable for future ground lease payments related to certain tower obligations. These contingent obligations are not included in the above table as the amounts owed are contractually owed by Crown Castle International Corp. based on the subleasing arrangement. See Note 9 - Tower Obligations for further information. Lessor Our leasing programs (“Leasing Programs”), which include JUMP! On Demand and the Sprint Flex Lease program acquired through the Merger, allow customers to lease a device (handset or tablet) over a period of, generally, 18 months and upgrade it for a new device when eligibility requirements are met. At the end of the initial term, customers are given the opportunity to return the device, purchase the device or extend the lease on a month-to-month basis. Upon device upgrade or at lease end, customers must return or purchase their device. The purchase price of the device is established at lease commencement and is based on the type of device leased and any down payment made. The Leasing Programs do not contain any residual value guarantees or variable lease payments, and there are no restrictions or covenants imposed by these leases. Leased wireless devices are included in Property and equipment, net in our Condensed Consolidated Balance Sheets. Through the Merger, we acquired leased wireless devices with a fair value of $5.8 billion as of April 1, 2020. The components of leased wireless devices under our Leasing Programs were as follows: (in millions) Average Remaining Useful Life September 30, 2020 December 31, 2019 Leased wireless devices, gross 10 months $ 7,436 $ 1,139 Accumulated depreciation (1,648) (407) Leased wireless devices, net $ 5,788 $ 732 For equipment revenues from the lease of mobile communication devices, see Note 10 - Revenue from Contracts with Cust o m e r s . Future minimum payments expected to be received over the lease term related to leased wireless devices, which exclude optional residual buy-out amounts at the end of the lease term, are summarized below: (in millions) Expected Payments Twelve Months Ending September 30, 2021 $ 2,315 2022 156 Total $ 2,471
Leases	Note 16 - Leases Lessee We are a lessee for non-cancelable operating and financing leases for cell sites, switch sites, retail stores, network equipment and office facilities with contractual terms that generally extend through 2035. Additionally, we lease dark fiber through non-cancelable operating leases with contractual terms that generally extend through 2041. The majority of cell site leases have an initial non-cancelable term of five five two Through the Merger, we acquired leases of real property, including cell sites, switch sites, dark fiber, retail stores and office facilities and recorded lease liabilities and associated right-of-use assets based on the discounted lease payments. Lease terms that are favorable or unfavorable to market terms were recorded as an adjustment to lease right-of-use assets on our Condensed Consolidated Balance Sheets. Favorable and unfavorable leases are amortized on a straight-line basis over the associated remaining lease term. On September 14, 2020, T-Mobile and American Tower Corporation (“American Tower”) entered into a lease agreement (the “American Tower Lease Agreement”) that will enable us to lease American Tower towers through April 2035 . The American Tower Lease Agreement extended the term and modified the rental payments for approximately 20,729 American Tower towers currently leased by us. As a result of this modification, we remeasured the associated right-of-use assets and lease liabilities resulting in an increase of $11.0 billion to each on the effective date of the modification . The components of lease expense were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Operating lease expense $ 1,259 $ 657 $ 3,082 $ 1,893 Financing lease expense: Amortization of right-of-use assets 183 146 508 376 Interest on lease liabilities 20 21 60 61 Total financing lease expense 203 167 568 437 Variable lease expense 106 62 239 185 Total lease expense $ 1,568 $ 886 $ 3,889 $ 2,515 Information relating to the lease term and discount rate is as follows: September 30, 2020 Weighted Average Remaining Lease Term (Years) Operating leases 10 Financing leases 3 Weighted Average Discount Rate Operating leases 4.0 % Financing leases 3.5 % Maturities of lease liabilities as of September 30, 2020, were as follows: (in millions) Operating Leases Finance Leases Twelve Months Ending September 30, 2021 $ 4,717 $ 1,100 2022 4,361 792 2023 3,754 426 2024 3,301 89 2025 2,785 61 Thereafter 19,184 72 Total lease payments 38,102 2,540 Less: imputed interest 7,786 117 Total $ 30,316 $ 2,423 Interest payments for financing leases were $19 million and $20 million for the three months ended September 30, 2020 and 2019, respectively, and $59 million and $61 million for the nine months ended September 30, 2020 and 2019, respectively. As of September 30, 2020, we have additional operating leases for cell sites and commercial properties that have not yet commenced with future lease payments of approximately $283 million. As of September 30, 2020, we were contingently liable for future ground lease payments related to certain tower obligations. These contingent obligations are not included in the above table as the amounts owed are contractually owed by Crown Castle International Corp. based on the subleasing arrangement. See Note 9 - Tower Obligations for further information. Lessor Our leasing programs (“Leasing Programs”), which include JUMP! On Demand and the Sprint Flex Lease program acquired through the Merger, allow customers to lease a device (handset or tablet) over a period of, generally, 18 months and upgrade it for a new device when eligibility requirements are met. At the end of the initial term, customers are given the opportunity to return the device, purchase the device or extend the lease on a month-to-month basis. Upon device upgrade or at lease end, customers must return or purchase their device. The purchase price of the device is established at lease commencement and is based on the type of device leased and any down payment made. The Leasing Programs do not contain any residual value guarantees or variable lease payments, and there are no restrictions or covenants imposed by these leases. Leased wireless devices are included in Property and equipment, net in our Condensed Consolidated Balance Sheets. Through the Merger, we acquired leased wireless devices with a fair value of $5.8 billion as of April 1, 2020. The components of leased wireless devices under our Leasing Programs were as follows: (in millions) Average Remaining Useful Life September 30, 2020 December 31, 2019 Leased wireless devices, gross 10 months $ 7,436 $ 1,139 Accumulated depreciation (1,648) (407) Leased wireless devices, net $ 5,788 $ 732 For equipment revenues from the lease of mobile communication devices, see Note 10 - Revenue from Contracts with Cust o m e r s . Future minimum payments expected to be received over the lease term related to leased wireless devices, which exclude optional residual buy-out amounts at the end of the lease term, are summarized below: (in millions) Expected Payments Twelve Months Ending September 30, 2021 $ 2,315 2022 156 Total $ 2,471

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 17 – Commitments and Contingencies Purchase Commitments We have commitments for non-dedicated transportation lines with varying expiration terms that generally extend through 2029. In addition, we have commitments to purchase wireless devices, network services, equipment, software, marketing sponsorship agreements and other items in the ordinary course of business, with various terms through 2050. Our purchase commitments, including purchase commitments assumed through the Merger, are approximately $4.2 billion for the year ending September 30, 2021, $3.4 billion in total for the years ending September 30, 2022 and 2023, $1.6 billion in total for the years ending September 30, 2024 and 2025 and $1.5 billion in total for the years thereafter. These amounts are not reflective of our entire anticipated purchases under the related agreements but are determined based on the non-cancelable quantities or termination amounts to which we are contractually obligated. Spectrum Leases In connection with the Merger, we assumed certain spectrum lease contracts from Sprint that include service obligations to the lessors. Certain of the spectrum leases provide for minimum lease payments, additional charges, renewal options and escalation clauses. Leased spectrum agreements have varying expiration terms that generally extend through 2050. We expect that all renewal periods in our spectrum leases will be exercised by us. Our spectrum lease and service credit commitments, including renewal periods, are approximately $328 million for the year ending September 30, 2021, $698 million in total for the years ending September 30, 2022 and 2023, $609 million in total for the years ending September 30, 2024 and 2025 and $5.1 billion in total for the years thereafter. We accrue a monthly obligation for the services and equipment based on the total estimated available service credits divided by the term of the lease. The obligation is reduced by services provided and as actual invoices are presented and paid to the lessors. The maximum remaining commitment on September 30, 2020 was $92 million and is expected to be incurred over the term of the related lease agreements, which generally range from 15 to 30 years. Merger Commitments In connection with the regulatory proceedings and approvals of the Transactions, we have commitments and other obligations to various state and federal agencies and certain nongovernmental organizations, including pursuant to the Consent Decree agreed to by us, DT, Sprint, SoftBank and DISH and entered by the U.S. District Court for the District of Columbia, and the FCC’s memorandum opinion and order approving our applications for approval of the Merger. These commitments and obligations include, among other things, extensive 5G network build-out commitments, obligations to deliver high-speed wireless services to the vast majority of Americans, including Americans residing in rural areas, and the marketing of an in-home broadband product where spectrum capacity is available. Other commitments relate to national security, pricing, service, employment and support of diversity initiatives. Many of the commitments specify time frames for compliance. Failure to fulfill our obligations and commitments in a timely manner could result in substantial fines, penalties, or other legal and administrative actions. Our monetary commitments associated with these matters are approximately $24 million for the year ended September 30, 2021, $36 million in total for the years ended September 30, 2022 and 2023 and $13 million in total for the years ended September 30, 2024 and 2025. These amounts do not represent our entire anticipated costs to achieve specified network coverage and performance requirements, employment targets or commitments to provide access to affordable rate plans, but represent only those amounts for which we are required to make a specified payment in connection with our commitments or settlements. Contingencies and Litigation Litigation Matters On February 28, 2020, we received a Notice of Apparent Liability for Forfeiture and Admonishment from the FCC (“FCC NAL”), which proposed a penalty against us for allegedly violating section 222 of the Communications Act and the FCC’s regulations governing the privacy of customer information. We recorded an accrual for an estimated payment amount as of September 30, 2020, which was included in Accounts payable and accrued liabilities in our Condensed Consolidated Balance Sheets. On April 1, 2020, in connection with the closing of the Merger, we assumed the contingencies and litigation matters of Sprint. Those matters include a wide variety of disputes, claims, government agency investigations and enforcement actions, and other proceedings, including, among other things, certain ongoing FCC and state government agency investigations into Sprint’s Lifeline program. In September 2019, Sprint notified the FCC that it had claimed monthly subsidies for serving subscribers even though these subscribers may not have met usage requirements under Sprint's usage policy for the Lifeline program, due to an inadvertent coding issue in the system used to identify qualifying subscriber usage that occurred in July 2017 while the system was being updated. Sprint has made a number of payments to reimburse the federal government and certain states for excess subsidy payments. Resolution of these matters could require making additional reimbursements and paying additional fines and penalties. We note that pursuant to Amendment No 2. to the Business Combination Agreement, SoftBank agreed to indemnify us against certain specified matters and losses. As of September 30, 2020, we have recorded contingent liabilities and an offsetting indemnification asset for the expected reimbursement by SoftBank (including the Lifeline matter noted above). Subsequent to September 30, 2020, we reached an agreement on certain matters, which will result in a payment of $200 million to resolve the FCC’s investigation. SoftBank has agreed to indemnify us for the settlement amount. We expect that any additional liabilities related to these indemnified matters would be indemnified and reimbursed by SoftBank. See Note 2 - Business Combination for further information. We are involved in various lawsuits and disputes, claims, government agency investigations and enforcement actions, and other proceedings (“Litigation Matters”) that arise in the ordinary course of business, which include claims of patent infringement (most of which are asserted by non-practicing entities primarily seeking monetary damages), class actions, and proceedings to enforce FCC rules and regulations. The Litigation Matters described above have progressed to various stages and some of them may proceed to trial, arbitration, hearing or other adjudication that could result in fines, penalties, or awards of monetary or injunctive relief in the coming 12 months if they are not otherwise resolved. We have established an accrual with respect to certain of these matters, where appropriate, which is reflected in the condensed consolidated financial statements but that is not considered to be, individually or in the aggregate, material. An accrual is established when we believe it is both probable that a loss has been incurred and an amount can be reasonably estimated. For other matters, where we have not determined that a loss is probable or because the amount of loss cannot be reasonably estimated, we have not recorded an accrual due to various factors typical in contested proceedings, including but not limited to uncertainty concerning legal theories and their resolution by courts or regulators, uncertain damage theories and demands, and a less than fully developed factual record. While we do not expect that the ultimate resolution of these proceedings, individually or in the aggregate, will have a material adverse effect on our financial position, an unfavorable outcome of some or all of these proceedings could have a material adverse impact on results of operations or cash flows for a particular period. This assessment is based on our current understanding of relevant facts and circumstances. As such, our view of these matters is subject to inherent uncertainties and may change in the future.

Restructuring Costs

Restructuring Costs	9 Months Ended
	Sep. 30, 2020
Restructuring and Related Activities [Abstract]
Restructuring Costs	Note 18 - Restructuring Costs Upon close of the Merger, we began implementing restructuring initiatives to realize cost efficiencies and reduce redundancies. The major activities associated with the restructuring initiatives to date, include contract termination costs associated with the rationalization of retail stores, distribution channels, duplicative backhaul services and other agreements, severance costs associated with the integration of redundant processes and functions and the decommissioning of network infrastructure including cell sites and equipment to achieve synergies in network costs. The following table summarizes the expenses incurred in connection with our restructuring initiatives: Restructuring Expenses Incurred (in millions) Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Contract termination costs $ 56 $ 169 Severance costs 21 370 Network decommissioning 21 41 Total restructuring plan expenses $ 98 $ 580 The expenses associated with the restructuring initiatives are included in Costs of services and Selling, general and administrative in our Condensed Consolidated Statements of Comprehensive Income. No expenses were incurred related to our restructuring initiatives for the three and nine months ended September 30, 2019. Our restructuring initiatives also include the acceleration or termination of certain of our operating and financing leases for cell sites, switch sites, retail stores, network equipment and office facilities. Incremental expenses associated with accelerating amortization of the right-of-use assets on lease contracts were $80 million for both the three and nine months ended September 30, 2020 and are included within Costs of services and Selling, general and administrative in our Condensed Consolidated Statements of Comprehensive Income. The changes in the liabilities associated with our restructuring initiatives, including expenses incurred and cash payments, are as follows: (in millions) April 1, Expenses Incurred Cash Payments Adjustments for Non-Cash Items (1) September 30, 2020 Contract termination costs $ — $ 169 $ (74) $ (1) $ 94 Severance costs — 370 (174) (94) 102 Network decommissioning — 41 (20) (21) — Total $ — $ 580 $ (268) $ (116) $ 196 (1) Non-cash items consists of non-cash stock-based compensation included within Severance costs and the write-off of assets within Network decommissioning. The liabilities accrued in connection with our restructuring initiatives are presented in Accounts payable and accrued liabilities in our Condensed Consolidated Balance Sheets. Our restructuring activities are expected to occur over the next three years with substantially all costs incurred by fiscal year 2023. We are evaluating additional restructuring initiatives which are dependent on consultations and negotiation with certain counterparties and the expected impact on our business operations, which could affect the amount or timing of the restructuring costs and related payments.

Additional Financial Informatio

Additional Financial Information	9 Months Ended
	Sep. 30, 2020
Supplemental Financial Statement Elements [Abstract]
Additional Financial Information	Note 19 – Additional Financial Information Accounts Payable and Accrued Liabilities Accounts payable and accrued liabilities are summarized as follows: (in millions) September 30, 2020 December 31, Accounts payable $ 3,862 $ 4,322 Payroll and related benefits 1,151 802 Property and other taxes, including payroll 1,386 682 Interest 760 227 Commissions 321 251 Toll and interconnect 179 156 Advertising 107 127 Other 623 179 Accounts payable and accrued liabilities $ 8,389 $ 6,746 Book overdrafts included in accounts payable and accrued liabilities were $240 million and $463 million as of September 30, 2020 and December 31, 2019, respectively. Related Party Transactions Deutsche Telekom We have related party transactions associated with DT or its affiliates in the ordinary course of business, which are included in the condensed consolidated financial statements. On April 1, 2020, in connection with the closing of the Merger, we: • Repaid our $4.0 billion Incremental Term Loan Facility with DT, consisting of a $2.0 billion Incremental Term Loan Facility due 2022 and a $2.0 billion Incremental Term Loan Facility due 2024; • Terminated our revolving credit facility with DT; • Repurchased from DT $4.0 billion of indebtedness to affiliates, consisting of $2.0 billion of 5.300% Senior Notes due 2021 and $2.0 billion of 6.000% Senior Notes due 2024; • Amended the $1.25 billion of 5.125% Senior Notes due 2025 and $1.25 billion of 5.375% Senior Notes due 2027, which represent indebtedness to affiliates, to change the maturity dates thereof to April 15, 2021 and April 15, 2022, respectively (the “2025 and 2027 Amendments”); and • Made an additional payment for requisite consents to DT of $13 million. These payments were recognized as a reduction to Long-term debt to affiliates in our Condensed Consolidated Balance Sheets. On July 4, 2020, we redeemed $1.25 billion aggregate principal amount of our 5.125% Senior Notes to affiliates due 2021. Amounts associated with the debt owed to DT are reflected as “Short-term debt to affiliates” and “Long-term debt to affiliates” in our Condensed Consolidated Balance Sheets. Interest related to this debt is reflected as “Interest expense to affiliates” in our Condensed Consolidated Statements of Comprehensive Income. The following table summarizes the impact of significant transactions with DT or its affiliates included in Operating expenses in the Condensed Consolidated Statements of Comprehensive Income: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Discount related to roaming expenses $ — $ (1) $ (5) $ (3) Fees incurred for use of the T-Mobile brand 20 21 63 65 International long distance agreement 13 9 35 29 We have an agreement with DT in which we receive reimbursement of certain administrative expenses, which were $2 million and $3 million for the three months ended September 30, 2020 and 2019, respectively, and $5 million and $8 million for the nine months ended September 30, 2020 and 2019, respectively. Amounts due from and to DT related to these agreements are included in the Condensed Consolidated Balance Sheets as “Accounts Receivables from affiliates” and “Payables to affiliates,” respectively. SoftBank On June 22, 2020, we entered into a Master Framework Agreement and related transactions with SoftBank related to the SoftBank Monetization as described in Note 14 - SoftBank Equity Transaction . On July 27, 2020, in connection with the SoftBank Monetization, the Rights Offering exercise period closed, and on August 3, 2020, the Rights Offering closed, resulting in the sale of 19,750,000 shares of our common stock. On August 3, 2020, upon completion of the SoftBank Monetization, DT and SoftBank held, directly or indirectly, approximately 43.4% and 8.6%, respectively, of the outstanding T-Mobile common stock, with the remaining approximately 48.0% of the outstanding T-Mobile common stock held by other stockholders. As a result of the Proxy Agreements, DT has voting control as of August 3, 2020 over approximately 52.4% of the outstanding T-Mobile common stock. In addition, as provided for in the Master Framework Agreement, DT also holds certain call options over approximately 101.5 million shares of our common stock held by SBGC. Subsequent to September 30, 2020, on October 6, 2020, we assigned our rights under the T-Mobile Fixed-Price Call Option to DT and DT terminated its right to purchase shares from us under the DT Fixed-Price Call Option, resulting in derecognition of the related derivative asset and liability in equal and offsetting amounts such that there was no net impact to our Condensed Consolidated Statements of Comprehensive Income . Brightstar We have arrangements with Brightstar, a subsidiary of SoftBank, whereby Brightstar provides supply chain and inventory management services to us in our indirect channels. We are currently in the process of terminating and restructuring most of our arrangements with Brightstar, except for reverse logistics and trade-in services. Amounts included in our consolidated financial statements associated with these supply chain and inventory management arrangements with Brightstar were not material. For more information regarding our related party transactions with SoftBank, see Note 2 - Business Combination and Note 14 - SoftBank Equity Transaction of the Notes to the Condensed Consolidated Financial Statements. Supplemental Consolidated Statements of Cash Flows Information The following table summarizes T-Mobile’s supplemental cash flow information: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Interest payments, net of amounts capitalized $ 940 $ 327 $ 1,889 $ 912 Operating lease payments 1,349 703 3,493 2,094 Income tax payments 63 5 118 77 Non-cash investing and financing activities Non-cash beneficial interest obtained in exchange for securitized receivables 1,535 1,734 4,634 4,862 Non-cash consideration for the acquisition of Sprint — — 33,533 — Decrease in accounts payable and accrued liabilities for purchases of property and equipment (216) (460) (555) (906) Leased devices transferred from inventory to property and equipment 599 298 2,352 612 Returned leased devices transferred from property and equipment to inventory (433) (65) (1,030) (189) Short-term debt assumed for financing of property and equipment — 475 38 775 Operating lease right-of-use assets obtained in exchange for lease obligations 11,833 989 13,046 3,083 Financing lease right-of-use assets obtained in exchange for lease obligations 219 395 912 943

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	Note 20 – Subsequent Events Subsequent to September 30, 2020, on October 6, 2020, we assigned our rights under the T-Mobile Fixed-Price Call Option to DT and DT terminated its right to purchase shares from us under the DT Fixed-Price Call Option, resulting in derecognition of the related derivative asset and liability in equal and offsetting amounts such that there was no net impact to our Condensed Consolidated Statements of Comprehensive Income. Subsequent to September 30, 2020, on October 6, 2020, T-Mobile USA issued $500 million of 2.050% Senior Secured Notes due 2028, $750 million of 2.550% Senior Secured Notes due 2031, $1.25 billion of 3.000% Senior Secured Notes due 2041, and $1.5 billion of 3.300% Senior Secured Notes due 2051. On October 9, 2020, we used the net proceeds of $4.0 billion to repay at par all of the outstanding amounts under, and terminate, the New Secured Term Loan Facility. Subsequent to September 30, 2020, on October 28, 2020, T-Mobile USA issued $1.0 billion of 2.250% Senior Secured Notes due 2031, $1.25 billion of 3.000% Senior Secured Notes due 2041, $1.5 billion of 3.300% Senior Secured Notes due 2051 and $1.0 billion of 3.600% Senior Secured Notes due 2060. We intend to use the net proceeds for general corporate purposes, which may include among other things, acquisitions of additional spectrum and refinancing existing indebtedness on an ongoing basis. Subsequent to September 30, 2020, on October 30, 2020, we entered into a $5.0 billion senior secured term loan commitment with certain financial institutions. Up to $5.0 billion of loans under the commitment may be drawn at any time (subject to customary conditions precedent) through June 30, 2021. If drawn, the facility matures in 364 days with one six-month extension exercisable at our discretion. Proceeds may be used for general corporate purposes and will accrue interest at a rate of LIBOR plus a margin of 1.25% per annum. Subsequent to September 30, 2020, on November 2, 2020, we extended the scheduled expiration date of our EIP sales arrangement to November 18, 2021. Subsequent to September 30, 2020, we reached an agreement on certain matters, which will result in a payment of $200 million to resolve the FCC’s investigation. SoftBank has agreed to indemnify us for the settlement amount.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation	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, 2019.
Basis of Accounting	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 which affect the financial statements and accompanying notes.
Use of Estimates	Estimates are based on historical experience, where applicable, and other assumptions which our management believes are reasonable under the circumstances, including but not limited to the valuation of assets acquired and liabilities assumed through the Merger with Sprint and the potential impacts arising from the COVID-19 pandemic. These estimates are inherently subject to judgment and actual results could differ from those estimates.
Restricted Cash	Restricted CashCertain provisions of our debt agreements require us to maintain specified cash collateral balances. Amounts associated with these balances are considered to be restricted cash and are included within Other assets in our Condensed Consolidated Balance Sheets.
Accounting Pronouncements Adopted During the Current Year/Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Adopted During the Current Year Receivables and Expected Credit Losses In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” and has since modified the standard with several ASUs (collectively, the “new credit loss standard”). The new credit loss standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions and reasonable and supportable forecasts that affect the collectibility of the reported amount. The new credit loss standard became effective for us, and we adopted the standard, on January 1, 2020. The new credit loss standard required a cumulative-effect adjustment to Accumulated deficit at the date of initial application, and as a result, we did not restate prior periods presented in the condensed consolidated financial statements. Under the new credit loss standard, we recognize lifetime expected credit losses at the inception of our credit risk exposures whereas we previously recognized credit losses only when it was probable that they had been incurred. We also recognize expected credit losses on our EIP receivables, which are inclusive of all installment receivables acquired in the Merger or issued thereafter, separately from, and in addition to, any unamortized discount on those receivables. Prior to the adoption of the new credit loss standard, we had offset our estimate of probable losses on our EIP receivables by the amount of the related unamortized discounts on those receivables. We have developed an expected credit loss model incorporating forward-looking loss indicators. The cumulative effect of initially applying the new credit loss standard on our receivables portfolio on January 1, 2020 was an increase to our allowance for credit losses of $91 million, a decrease to our net deferred tax liabilities of $24 million and an increase to our Accumulated deficit of $67 million. For EIP receivables acquired in the Merger, we also recognize expected credit losses separately from, and in addition to, the acquisition date fair value of the acquired EIP receivables. Accounts Receivable Portfolio Segment Accounts receivable consists primarily of amounts currently due from customers (e.g., for wireless services and monthly device lease payments), handset insurance administrators, wholesale partners, other carriers and third-party retail channels. Accounts receivable are presented in our Condensed Consolidated Balance Sheets at the amortized cost basis (i.e., the receivables’ outstanding principal balance adjusted for any write-offs), net of the allowance for expected credit losses. We have an arrangement to sell certain of our customer service accounts receivable on a revolving basis, which are treated as sales of financial assets. Equipment Installment Plan Receivables Portfolio Segment We offer certain retail customers the option to pay for their devices and other purchases in installments, generally over a period of 24 months using an EIP. EIP receivables are presented in our Condensed Consolidated Balance Sheets at the amortized cost basis (i.e., the receivables’ unpaid principal balance adjusted for any write-offs and unamortized discounts), net of the allowance for expected credit losses. At the time of an installment sale, we impute a discount for interest if the term exceeds 12 months as there is no stated rate of interest on the receivables. The receivables are recorded at their present value, which is determined by discounting expected future cash payments at the imputed interest rate. This adjustment results in a discount which is allocated to the performance obligations of the arrangement and recorded as a reduction in transaction price in Total service revenues and Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income. The imputed discount rate is the current market interest rate and is predominately comprised of the estimated credit risk underlying the EIP receivable, reflecting the estimated credit worthiness of the customer. The imputed discount on receivables is amortized over the financed installment term using the effective interest method and recognized as Other revenues in our Condensed Consolidated Statements of Comprehensive Income. At the time that we originate EIP loans to customers, we recognize an allowance for credit losses that we expect to incur over the lifetime of such assets. This allowance represents the portion of the amortized cost basis of EIP receivables that we do not expect to collect. The current portion of the EIP receivables is included in Equipment installment plan receivables, net and the long-term portion of the EIP receivables is included in Equipment installment plan receivables due after one year, net in our Condensed Consolidated Balance Sheets. We have an arrangement to sell certain EIP receivables on a revolving basis, which are treated as sales of financial assets. Allowance for Credit Losses We maintain an allowance for expected credit losses and determine its appropriateness through an established process that assesses the lifetime credit losses that we expect to incur related to our receivable portfolio. Each period, management assesses the appropriateness of the level of allowance for credit losses by considering credit risk inherent within the portfolio of receivables, as of period end. We develop and document our allowance methodology for each of our accounts receivable and EIP receivable portfolio segments. While we attribute portions of the allowance to our respective accounts receivable and EIP portfolio segments, the entire allowance is available to absorb expected credit losses related to the total receivable portfolio. Determining the appropriate level of allowance for credit losses requires significant judgment. Our process involves procedures to appropriately consider the unique risk characteristics of our accounts receivable and EIP receivable portfolio segments. For each portfolio segment, losses are estimated collectively for groups of receivables with similar characteristics. Our allowance levels are influenced by receivable volumes, receivable delinquency status, historical loss experience and other conditions influencing loss expectations, such as changes in credit and collections policies and forecasts of macro-economic conditions. Total imputed discount and allowances, which includes all accounts receivable and EIP receivables acquired in the Merger or issued thereafter, were approximately 7.8% and 7.0% of the total amount of gross accounts receivable, including EIP receivables, at September 30, 2020 and December 31, 2019, respectively. We consider a receivable past due when a customer has not paid us by the contractually specified payment due date. Account balances are written off against the allowance for credit losses if collection efforts are unsuccessful and the receivable balance is deemed uncollectible, based on factors such as customer credit ratings as well as the length of time the amounts are past due. If there is a deterioration of our customers’ financial condition or if future actual default rates on receivables in general differ from those currently anticipated, we will adjust our allowance for credit losses accordingly, which may materially affect our financial results in the period the adjustments are made. Cloud Computing Arrangements In August 2018, the FASB issued ASU 2018-15, “Intangibles - Goodwill and Other - Internal-Use Software (Topic 350): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract.” The standard aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The standard also requires the presentation of the amortization of the capitalized implementation costs in the same line item in the Condensed Consolidated Statements of Comprehensive Income as the fees associated with the hosting arrangement. The standard became effective for us, and we adopted the standard, on January 1, 2020. We adopted the standard on a prospective basis applying it to implementation costs incurred subsequent to January 1, 2020 and as a result did not restate the prior periods presented in the condensed consolidated financial statements. The adoption of the standard did not have a material impact on our condensed consolidated financial statements for the nine months ended September 30, 2020. Income Taxes In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” The standard removes certain exceptions to the general principles in Topic 740. We early adopted the standard on January 1, 2020 and have applied the standard retrospectively to all periods presented. The adoption of this standard did not have a material impact on our condensed consolidated financial statements for the nine months ended September 30, 2020. Guarantor Financial Information On March 2, 2020, the Securities and Exchange Commission (the “SEC”) adopted amendments to the financial disclosure requirements for guarantors and issuers of guaranteed securities, as well as for affiliates whose securities collateralize a registrant’s securities. The amendments revise Rules 3-10 and 3-16 of Regulation S-X, and relocate part of Rule 3-10 and all of Rule 3-16 to the new Article 13 in Regulation S-X, which is comprised of new Rules 13-01 and 13-02. We early adopted the requirements of the amendments on January 1, 2020, which included replacing guarantor condensed consolidating financial information with summarized financial information for the consolidated obligor group (Parent, Issuer, and Guarantor Subsidiaries) as well as no longer requiring guarantor cash flow information, financial information for non-guarantor subsidiaries, and a reconciliation to the consolidated results. Accounting Pronouncements Not Yet Adopted Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the SEC did not have, or are not expected to have, a significant impact on our present or future condensed consolidated financial statements.

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Schedule of Components of Consideration Transferred	The acquisition-date fair value of consideration transferred in the Merger totaled $40.8 billion, comprised of the following: (in millions) April 1, 2020 Fair value of T-Mobile common stock issued to Sprint stockholders (1) $ 31,328 Fair value of T-Mobile replacement equity awards attributable to pre-combination service (2) 323 Repayment of Sprint’s debt (including accrued interest and prepayment penalties) (3) 7,396 Value of contingent consideration (4) 1,882 Payment received from selling stockholder (5) (102) Total consideration exchanged $ 40,827 (1) Represents the fair value of T-Mobile common stock issued to Sprint stockholders pursuant to the Business Combination Agreement, less shares surrendered by SoftBank pursuant to the Letter Agreement. The fair value is based on 373,396,310 shares of Sprint common stock issued and outstanding as of March 31, 2020, an exchange ratio of 0.10256 shares of T-Mobile common stock per share of Sprint common stock, less 48,751,557 T-Mobile shares surrendered by SoftBank which are treated as contingent consideration, and the closing price per share of T-Mobile common stock on NASDAQ on March 31, 2020, of $83.90, as shares were transferred to Sprint stockholders prior to the opening of markets on April 1, 2020. (2) Equity-based awards held by Sprint employees prior to the acquisition date have been replaced with T-Mobile equity-based awards. The portion of the equity-based awards that relates to services performed by the employee prior to the acquisition date is included within consideration transferred, and includes stock options, restricted stock units and performance-based restricted stock units. (3) Represents the cash consideration paid concurrent with the close of the Merger to retire certain Sprint debt, as required by change in control provisions of the debt, plus interest and prepayment penalties. (4) Represents the fair value of the SoftBank Specified Shares Amount contingent consideration that may be issued as set forth in the Letter Agreement. (5) Represents receipt of a cash payment from SoftBank for certain expenses associated with the Merger and is presented in Cash paid for acquisition of companies, net of cash acquired within our Condensed Consolidated Statements of Cash Flows.
Schedule of Amounts Recognized as of Acquisition Date	The following table summarizes the preliminary fair values for each major class of assets acquired and liabilities assumed at the acquisition date. We retained the services of certified valuation specialists to assist with assigning estimated values to certain acquired assets and assumed liabilities. We are in the process of finalizing the valuation of the assets acquired and liabilities assumed including income tax related amounts. Therefore, the preliminary fair values set forth below are subject to further adjustment as additional information is obtained and the valuations are completed. (in millions) April 1, 2020 Cash and cash equivalents $ 2,214 Accounts receivable 1,650 Equipment installment plan receivables 1,024 Inventory 658 Prepaid expenses 140 Assets held for sale 1,908 Other current assets 642 Property and equipment 17,230 Operating lease right-of-use assets 6,583 Financing lease right-of-use assets 291 Goodwill 9,194 Spectrum licenses 45,400 Other intangible assets 6,325 Equipment installment plan receivables due after one year, net 247 Other assets (1) 541 Total assets acquired 94,047 Accounts payable and accrued liabilities 4,907 Short-term debt 2,760 Deferred revenue 508 Short-term operating lease liabilities 1,818 Short-term financing lease liabilities 8 Liabilities held for sale 475 Other current liabilities 650 Long-term debt 29,037 Tower obligations 950 Deferred tax liabilities 3,866 Operating lease liabilities 5,615 Financing lease liabilities 12 Other long-term liabilities 2,614 Total liabilities assumed 53,220 Total consideration transferred $ 40,827 (1) Included in Other assets acquired is $80 million in restricted cash.
Schedule of Pro Forma Information	The following unaudited pro forma financial information gives effect to the Transactions as if they had been completed on January 1, 2019. The unaudited pro forma information was prepared in accordance with the requirements of ASC 805, which is a different basis than pro forma information prepared under Article 11 of Regulation S-X (“Article 11”). As such, they are not directly comparable with historical results for stand-alone T-Mobile prior to April 1, 2020, historical results for T-Mobile from April 1, 2020 that reflect the Transactions and are inclusive of the results and operations of Sprint, nor our previously provided pro forma financials prepared in accordance with Article 11. The pro forma results for the three and nine months ended September 30, 2020 and 2019, include the impact of several adjustments to previously reported operating results. The pro forma adjustments are based on historically reported transactions by the respective companies. The pro forma results do not include any anticipated synergies or other expected benefits of the acquisition. Three Months Ended September 30, Nine Months Ended September 30, (in millions, except per share amounts) 2020 2019 2020 2019 Total revenues $ 19,269 $ 17,243 $ 54,342 $ 52,322 Income (loss) from continuing operations 1,359 451 2,455 (628) Income from discontinued operations, net of tax — 393 677 1,239 Net income 1,359 849 3,132 623

Receivables and Expected Cred_2

Receivables and Expected Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
Schedule of Equipment Installment Plan Receivables	The following table summarizes the EIP receivables, including imputed discounts and related allowance for credit losses: (in millions) September 30, 2020 December 31, EIP receivables, gross (1) $ 5,018 $ 4,582 Unamortized imputed discount (248) (299) EIP receivables, net of unamortized imputed discount 4,770 4,283 Allowance for credit losses (2) (289) (100) EIP receivables, net of allowance for credit losses and imputed discount $ 4,481 $ 4,183 Classified on the balance sheet as: Equipment installment plan receivables, net of allowance for credit losses and imputed discount $ 3,083 $ 2,600 Equipment installment plan receivables due after one year, net of allowance for credit losses and imputed discount 1,398 1,583 EIP receivables, net of allowance for credit losses and imputed discount $ 4,481 $ 4,183 (1) Through the Merger, we acquired EIP receivables with a fair value of $1.3 billion as of April 1, 2020. As they were recorded at fair value, an imputed discount was not recognized on the acquired receivables. (2) Allowance for credit losses as of September 30, 2020 was impacted by the cumulative effect of initially applying the new credit loss standard on our receivables portfolio on January 1, 2020, which resulted in an increase to our allowance for credit losses of $91 million.
Schedule of Equipment Installment Plan Receivables by Credit Category	The following table presents the amortized cost of our EIP receivables by delinquency status, customer credit class, and year of origination as of September 30, 2020. Originated in 2020 Originated in 2019 Originated prior to 2019 Total EIP Receivables, net of (in millions) Prime Subprime Prime Subprime Prime Subprime Prime Subprime Grand total Current - 30 days past due $ 1,540 $ 1,453 $ 766 $ 654 $ 193 $ 66 $ 2,499 $ 2,173 $ 4,672 31 - 60 days past due 9 19 8 13 1 1 18 33 51 61 - 90 days past due 2 7 2 5 1 1 5 13 18 More than 90 days past due 3 8 4 10 1 3 8 21 29 EIP receivables, net of unamortized imputed discount $ 1,554 $ 1,487 $ 780 $ 682 $ 196 $ 71 $ 2,530 $ 2,240 $ 4,770
Schedule of Unamortized Imputed Discount and Allowance for Credit Losses for Equipment Installment Plan Receivables	Activity for the nine months ended September 30, 2020 and 2019, in the allowance for credit losses and unamortized imputed discount balances for the accounts receivable and EIP receivables segments were as follows: September 30, 2020 September 30, 2019 (in millions) Accounts Receivable Allowance EIP Receivables Allowance Total Accounts Receivable Allowance EIP Receivables Allowance Total Allowance for credit losses and imputed discount, beginning of period $ 61 $ 399 $ 460 $ 67 $ 449 $ 516 Beginning balance adjustment due to implementation of the new credit loss standard — 91 91 — — — Bad debt expense 261 228 489 51 167 218 Write-offs, net of recoveries (114) (130) (244) (57) (185) (242) Change in imputed discount on short-term and long-term EIP receivables N/A 60 60 N/A 91 91 Impact on the imputed discount from sales of EIP receivables N/A (111) (111) N/A (127) (127) Allowance for credit losses and imputed discount, end of period $ 208 $ 537 $ 745 $ 61 $ 395 $ 456

Sales of Certain Receivables (T

Sales of Certain Receivables (Tables)	9 Months Ended
	Sep. 30, 2020
Transfers and Servicing [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the carrying amounts and classification of assets, which consist primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to our variable interest in the Service VIE: (in millions) September 30, December 31, Other current assets $ 386 $ 350 Accounts payable and accrued liabilities 65 25 Other current liabilities 371 342
Schedule of variable interest entities - EIP	The following table summarizes the carrying amounts and classification of assets, which consist primarily of the deferred purchase price, and liabilities included in our Condensed Consolidated Balance Sheets that relate to the EIP BRE: (in millions) September 30, 2020 December 31, Other current assets $ 353 $ 344 Other assets 109 89 Other long-term liabilities 8 18
Schedule of Factoring Arrangement	The following table summarizes the impact of the sale of certain service receivables and EIP receivables in our Condensed Consolidated Balance Sheets: (in millions) September 30, 2020 December 31, Derecognized net service receivables and EIP receivables $ 2,535 $ 2,584 Other current assets 739 694 of which, deferred purchase price 737 692 Other long-term assets 109 89 of which, deferred purchase price 109 89 Accounts payable and accrued liabilities 65 25 Other current liabilities 371 342 Other long-term liabilities 8 18 Net cash proceeds since inception 1,845 1,944 Of which: Change in net cash proceeds during the year-to-date period (99) 65 Net cash proceeds funded by reinvested collections 1,944 1,879

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	The components of property and equipment were as follows: (in millions) Useful Lives September 30, 2020 December 31, Land $ 236 $ — Buildings and equipment Up to 40 years 3,872 2,587 Wireless communications systems Up to 20 years 45,666 34,353 Leasehold improvements Up to 12 years 1,750 1,345 Capitalized software Up to 10 years 15,703 12,705 Leased wireless devices Up to 19 months 7,436 1,139 Construction in progress 4,180 2,973 Accumulated depreciation and amortization (40,276) (33,118) Property and equipment, net $ 38,567 $ 21,984
Schedule of Asset Retirement Obligations	Activity in our asset retirement obligations was as follows: (in millions) Nine Months Ended September 30, 2020 Twelve Months Ended Asset retirement obligations, beginning of year $ 659 $ 609 Fair value of liabilities acquired through Merger 1,062 — Liabilities incurred 9 35 Liabilities settled (16) (2) Accretion expense 37 32 Changes in estimated cash flows — (15) Asset retirement obligations, end of period $ 1,751 $ 659 Classified on the balance sheet as: Other long-term liabilities $ 1,751 $ 659

Goodwill, Spectrum License Tr_2

Goodwill, Spectrum License Transactions and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the nine months ended September 30, 2020 and year ended December 31, 2019, are as follows: (in millions) Goodwill Historical goodwill, net of accumulated impairment losses of $10,766 $ 1,901 Goodwill from acquisition in 2019 29 Balance as of December 31, 2019 1,930 Goodwill from acquisition of Sprint 9,194 Layer3 goodwill impairment (218) Balance as of September 30, 2020 $ 10,906 Accumulated impairment losses at September 30, 2020 $ (10,985)
Schedule of Fair Value of Intangible Assets Acquired in Merger	The following table summarizes the fair value of the intangible assets acquired in the Merger: Weighted Average Useful Life (in years) Fair Value as of April 1, 2020 Spectrum licenses Indefinite-lived $ 45,400 Tradenames (1) 2 years 207 Customer relationships 8 years 4,900 Favorable spectrum leases 18 years 790 Patent rights 7 years 51 Other intangible assets 7 years 377 Total intangible assets acquired $ 51,725 (1) Tradenames include the Sprint brand
Schedule of Spectrum Licenses	The following table summarizes our spectrum license activity for the nine months ended September 30, 2020: (in millions) Nine Months Ended September 30, 2020 Spectrum licenses, beginning of year $ 36,465 Spectrum license acquisitions 1,006 Spectrum licenses acquired in Merger 45,400 Costs to clear spectrum 20 Spectrum licenses, end of period $ 82,891
Schedule of Other Intangible Assets	The components of Other intangible assets were as follows: Useful Lives September 30, 2020 December 31, 2019 (in millions) Gross Amount Accumulated Amortization Net Amount Gross Amount Accumulated Amortization Net Amount Customer relationships Up to 8 years $ 6,004 $ (1,681) $ 4,323 $ 1,104 $ (1,104) $ — Tradenames and patents Up to 19 years 595 (364) 231 323 (258) 65 Favorable spectrum leases Up to 27 years 790 (23) 767 — — — Other Up to 10 years 477 (138) 339 100 (50) 50 Other intangible assets $ 7,866 $ (2,206) $ 5,660 $ 1,527 $ (1,412) $ 115
Schedule of Estimated Aggregate Future Amortization Expense	The estimated aggregate future amortization expense for intangible assets subject to amortization are summarized below: (in millions) Estimated Future Amortization Twelve Months Ending September 30, 2021 $ 1,318 2022 1,040 2023 866 2024 709 2025 551 Thereafter 1,176 Total $ 5,660

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Carrying Values and Fair Values of Long-term Debt	The carrying amounts and fair values of our short-term and long-term debt included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy September 30, 2020 December 31, 2019 (in millions) Carrying Amount (1) Fair Value (1) Carrying Amount (1) Fair Value (1) Liabilities: Senior Unsecured Notes to third parties 1 $ 30,078 $ 31,906 $ 10,958 $ 11,479 Senior Notes to affiliates 2 4,711 4,981 9,986 10,366 Senior Secured Notes to third parties 1 27,778 31,105 — — Incremental Term Loan Facility to affiliates 2 — — 4,000 4,000 Secured Term Loan Facility to third parties 1 3,890 3,990 — — (1) Excludes $312 million and $25 million as of September 30, 2020 and December 31, 2019, respectively, in vendor financing arrangements and other debt as the carrying values approximate fair value primarily due to the short-term maturities of these instruments.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Debt	The following table sets forth the debt balances and activity as of, and for the nine months ended, September 30, 2020 : (in millions) December 31, 2019 Proceeds from Issuances and Borrowings (1) Assumed Debt (2) Note Redemptions (1) Repayments (3) Reclassifications (1) Other (4) September 30, 2020 Short-term debt $ 25 $ 18,943 $ 2,760 $ (21,413) $ (2,355) $ 5,696 $ 57 $ 3,713 Long-term debt 10,958 26,595 29,037 — (2,310) (5,696) (239) 58,345 Total debt to third parties 10,983 45,538 31,797 (21,413) (4,665) — (182) 62,058 Short-term debt to affiliates — — — (3,235) — 3,231 4 — Long-term debt to affiliates 13,986 (13) — (6,041) — (3,231) 10 4,711 Total debt $ 24,969 $ 45,525 $ 31,797 $ (30,689) $ (4,665) $ — $ (168) $ 66,769 (1) Issuances and borrowings, note redemptions, and reclassifications are recorded net of related issuance costs, discounts and premiums. Includes the issuance of $200 million in vendor financing agreements and other debt as well as payments for requisite consents to DT and third-party note holders of $13 million and $95 million, respectively, made on April 1, 2020 in connection with the closing of the Merger, which were recognized as a reduction to Long-term debt in our Condensed Consolidated Balance Sheets. (2) In connection with the Merger, we assumed certain of Sprint’s indebtedness, as described below. (3) In conjunction with the Merger, the total principal amount outstanding under Sprint’s accounts receivable facility of $2.3 billion was repaid on April 1, 2020, and the facility was terminated. (4) Other includes the amortization of premiums, discounts, debt issuance costs and consent fees. During the nine months ended September 30, 2020, we issued the following Senior Secured Notes and entered into the following Secured loan facilities: (in millions) Principal Issuances Discounts and Issuance Costs Net Proceeds from Issuance of Long-Term Debt Issue Date 3.500% Senior Secured Notes due 2025 $ 3,000 $ 12 $ 2,988 April 9, 2020 3.750% Senior Secured Notes due 2027 4,000 17 3,983 April 9, 2020 3.875% Senior Secured Notes due 2030 7,000 78 6,922 April 9, 2020 4.375% Senior Secured Notes due 2040 2,000 47 1,953 April 9, 2020 4.500% Senior Secured Notes due 2050 3,000 24 2,976 April 9, 2020 1.500% Senior Secured Notes due 2026 1,000 5 995 June 24, 2020 2.050% Senior Secured Notes due 2028 1,250 8 1,242 June 24, 2020 2.550% Senior Secured Notes due 2031 1,750 12 1,738 June 24, 2020 Total of Senior Secured Notes issued 23,000 203 22,797 Secured bridge loan facility due 2021 19,000 257 18,743 April 1, 2020 Secured term loan facility due 2027 4,000 107 3,893 April 1, 2020 Total of Secured loan facilities issued 23,000 364 22,636 Total Issuances and Borrowings $ 46,000 $ 567 $ 45,433 In connection with the Merger, we assumed the following indebtedness of Sprint: (in millions) Fair value as of April 1, 2020 Principal Outstanding as of September 30, 2020 Carrying Value as of September 30, 2020 7.250% Senior Notes due 2021 $ 2,324 $ 2,250 $ 2,300 7.875% Senior Notes due 2023 4,682 4,250 4,624 7.125% Senior Notes due 2024 2,746 2,500 2,720 7.625% Senior Notes due 2025 1,677 1,500 1,661 7.625% Senior Notes due 2026 1,701 1,500 1,687 3.360% Senior Secured Series 2016-1 A-1 Notes due 2021 (1) 1,310 875 874 4.738% Senior Secured Series 2018-1 A-1 Notes due 2025 (1) 2,153 2,100 2,148 5.152% Senior Secured Series 2018-1 A-2 Notes due 2028 (1) 1,960 1,838 1,953 7.000% Senior Notes due 2020 1,510 — — 11.500% Senior Notes due 2021 1,105 1,000 1,074 6.000% Senior Notes due 2022 2,372 2,280 2,355 6.875% Senior Notes due 2028 2,834 2,475 2,817 8.750% Senior Notes due 2032 2,649 2,000 2,630 Accounts receivable facility 2,310 — — Other debt 464 336 312 Total Debt Assumed $ 31,797 $ 24,904 $ 27,155
Debt Instrument Redemption	During the nine months ended September 30, 2020, we repaid the following loan facilities and redeemed the following Senior Notes held by third parties and Senior Notes held by affiliates: (in millions) Principal Amount Write-off of Premiums and Issuance Costs (1) Other (2) Redemption or Repayment Date Redemption Price Secured bridge loan facility due 2021 $ 19,000 $ 251 $ (47) April 9, 2020 100.128 % 6.500% Senior Notes due 2024 1,000 12 22 July 4, 2020 102.167 % 6.375% Senior Notes due 2025 1,700 24 36 September 1, 2020 102.125 % Total of Secured bridge loan facility and Senior Notes to third parties redeemed 21,700 287 11 5.300% Senior Notes to affiliates due 2021 (3) 2,000 — — April 1, 2020 100.000 % 6.000% Senior Notes to affiliates due 2024 (3) 1,350 (26) — April 1, 2020 100.000 % 6.000% Senior Notes to affiliates due 2024 (3) 650 (15) — April 1, 2020 100.000 % Incremental term loan facility to affiliates due 2022 2,000 — — April 1, 2020 100.000 % Incremental term loan facility to affiliates due 2024 2,000 — — April 1, 2020 100.000 % 5.125% Senior Secured Notes to affiliates due 2021 1,250 15 — July 4, 2020 100.000 % Total of Senior Notes and Incremental term loan facilities to affiliates redeemed 9,250 (26) — Total Redemptions $ 30,950 $ 261 $ 11 Accounts receivable facility $ 2,310 $ — $ — April 1, 2020 100.00 % 3.360% Senior Secured Series 2016-1 A-1 Notes due 2021 438 — — Various N/A 7.000% Senior Notes due 2020 1,500 — — August 15, 2020 N/A Secured term loan facility due 2027 10 — — September 29, 2020 N/A Other debt 407 — — Various N/A Total Repayments $ 4,665 $ — $ — (1) Write-off of premiums, discounts and issuance costs are included in Other expense, net in our Condensed Consolidated Statements of Comprehensive Income. Write-off of issuance costs are included in Loss on redemption of debt within Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows. (2) Primarily represents a reimbursement of a portion of the commitment letter fees that were paid to financial institutions when we drew down on the Secured Bridge Loan Facility on April 1, 2020 and is included in Other expense, net in our Condensed Consolidated Statements of Comprehensive Income. (3) Pursuant to the Financing Matters Agreement, the Senior Notes were effectively redeemed through a repurchase and were cancelled and retired in full on April 1, 2020.

Tower Obligations (Tables)

Tower Obligations (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Summary of Impacts to Consolidated Balance Sheets	The following table summarizes the balances associated with both of the tower arrangements in the Condensed Consolidated Balance Sheets: (in millions) September 30, 2020 December 31, 2019 Property and equipment, net $ 1,544 $ 198 Tower obligations 3,079 2,236

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	Postpaid service revenues, including postpaid phone revenues and postpaid other revenues, were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Postpaid service revenues Postpaid phone revenues $ 9,532 $ 5,400 $ 24,450 $ 15,870 Postpaid other revenues 677 346 1,605 982 Total postpaid service revenues $ 10,209 $ 5,746 $ 26,055 $ 16,852 Equipment revenues from the lease of mobile communication devices were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Equipment revenues from the lease of mobile communication devices $ 1,350 $ 142 $ 2,936 $ 446
Schedule of Contract Liability and Receivable Balances	The opening and closing balances of our contract asset and contract liability balances from contracts with customers as of December 31, 2019 and September 30, 2020, were as follows: (in millions) Contract Assets Contract Liabilities Balance as of December 31, 2019 $ 63 $ 560 Balance as of September 30, 2020 243 783 Change $ 180 $ 223 Revenues for the three and nine months ended September 30, 2020 and 2019, include the following: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Amounts included in the beginning of year contract liability balance $ 5 $ 39 $ 543 $ 642

Employee Compensation and Ben_2

Employee Compensation and Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Stock-based Compensation Expense and Related Income Tax Benefits	Stock-based compensation expense and related income tax benefits were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions, except shares, per share and contractual life amounts) 2020 2019 2020 2019 Stock-based compensation expense $ 161 $ 126 $ 558 $ 366 Income tax benefit related to stock-based compensation $ 34 $ 25 $ 105 $ 70 Weighted average fair value per stock award granted $ 114.52 $ 77.41 $ 97.28 $ 73.18 Unrecognized compensation expense $ 670 $ 631 $ 670 $ 631 Weighted average period to be recognized (years) 1.9 1.8 1.9 1.8 Fair value of stock awards vested $ 264 $ 14 $ 1,079 $ 356
Schedule of RSU and PRSU Awards Activity	Time-Based Restricted Stock Units and Restricted Stock Awards (in millions, except shares, per share and contractual life amounts) Number of Units or Awards Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested, December 31, 2019 10,503,211 $ 67.31 0.9 $ 824 Assumed through acquisition 1,852,527 83.90 Granted 5,598,737 95.56 Vested (6,151,759) 69.74 Forfeited (861,098) 84.14 Nonvested, September 30, 2020 10,941,618 81.90 1.0 1,251 Performance-Based Restricted Stock Units and Restricted Stock Awards (in millions, except shares, per share and contractual life amounts) Number of Units or Awards Weighted Average Grant Date Fair Value Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Nonvested, December 31, 2019 3,803,539 $ 69.78 1.0 $ 300 Assumed through acquisition 3,535,384 83.90 Granted 1,962,547 105.49 Vested (5,120,598) 76.32 Forfeited (136,359) 83.90 Nonvested, September 30, 2020 4,044,513 83.69 0.9 465 PRSUs included in the table above are shown at target. Share payout can range from 0% to 200% based on different performance outcomes. Weighted average grant date fair value of RSU and PRSU assumed through acquisition is based on the fair value on the date assumed.
Schedule of Stock Options Activity	The following activity occurred under the Stock Option Plans: Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Outstanding at December 31, 2019 194,942 $ 13.80 2.9 Assumed through acquisition 1,635,518 33.37 Exercised (794,853) 52.27 Expired/canceled (4,296) 41.82 Outstanding at September 30, 2020 1,031,311 52.51 4.1 Exercisable at September 30, 2020 1,029,731 52.55 4.1 Weighted average grant date fair value of stock options assumed through acquisition is based on the fair value on the date assumed.
Components of Net Expense Recognized for Pension Plan	The components of net expense recognized for the Pension Plan were as follows: (in millions) Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Interest on projected benefit obligations $ 18 $ 35 Expected return on pension plan assets (15) (30) Net pension expense $ 3 $ 5

Discontinued Operations (Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Components of Discontinued Operations	The components of discontinued operations from the Merger close date of April 1, 2020, through September 30, 2020, were as follows: (in millions) Nine Months Ended September 30, 2020 Major classes of line items constituting pretax income from discontinued operations Prepaid revenues $ 973 Roaming and other service revenues 27 Total service revenues 1,000 Equipment revenues 270 Total revenues 1,270 Cost of services 25 Cost of equipment sales 499 Selling, general and administrative 314 Total operating expenses 838 Pretax income from discontinued operations 432 Income tax expense (112) Income from discontinued operations $ 320

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	The computation of basic and diluted earnings per share was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions, except shares and per share amounts) 2020 2019 2020 2019 Income from continuing operations $ 1,253 $ 870 $ 1,994 $ 2,717 Income from discontinued operations, net of tax — — 320 — Net income $ 1,253 $ 870 $ 2,314 $ 2,717 Weighted average shares outstanding - basic 1,238,450,665 854,578,241 1,111,511,964 853,391,370 Effect of dilutive securities: Outstanding stock options and unvested stock awards 11,348,075 8,112,510 10,528,564 9,463,284 Weighted average shares outstanding - diluted 1,249,798,740 862,690,751 1,122,040,528 862,854,654 Basic earnings per share: Continuing operations $ 1.01 $ 1.02 $ 1.79 $ 3.18 Discontinued operations — — 0.29 — Earnings per share - basic $ 1.01 $ 1.02 $ 2.08 $ 3.18 Diluted earnings per share: Continuing operations $ 1.00 $ 1.01 $ 1.78 $ 3.15 Discontinued operations — — 0.28 — Earnings per share - diluted $ 1.00 $ 1.01 $ 2.06 $ 3.15 Potentially dilutive securities: Outstanding stock options and unvested stock awards 54,485 241 30,469 30,314 SoftBank contingent consideration 48,751,557 — 32,738,272 —

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Operating lease expense $ 1,259 $ 657 $ 3,082 $ 1,893 Financing lease expense: Amortization of right-of-use assets 183 146 508 376 Interest on lease liabilities 20 21 60 61 Total financing lease expense 203 167 568 437 Variable lease expense 106 62 239 185 Total lease expense $ 1,568 $ 886 $ 3,889 $ 2,515
Schedule of Information Relating to Lease Term and Discount Rate	Information relating to the lease term and discount rate is as follows: September 30, 2020 Weighted Average Remaining Lease Term (Years) Operating leases 10 Financing leases 3 Weighted Average Discount Rate Operating leases 4.0 % Financing leases 3.5 %
Maturity Schedule of Operating Lease Liabilities	Maturities of lease liabilities as of September 30, 2020, were as follows: (in millions) Operating Leases Finance Leases Twelve Months Ending September 30, 2021 $ 4,717 $ 1,100 2022 4,361 792 2023 3,754 426 2024 3,301 89 2025 2,785 61 Thereafter 19,184 72 Total lease payments 38,102 2,540 Less: imputed interest 7,786 117 Total $ 30,316 $ 2,423
Maturity Schedule of Finance Lease Liabilities	Maturities of lease liabilities as of September 30, 2020, were as follows: (in millions) Operating Leases Finance Leases Twelve Months Ending September 30, 2021 $ 4,717 $ 1,100 2022 4,361 792 2023 3,754 426 2024 3,301 89 2025 2,785 61 Thereafter 19,184 72 Total lease payments 38,102 2,540 Less: imputed interest 7,786 117 Total $ 30,316 $ 2,423
Schedule of Leased Wireless Devices	The components of leased wireless devices under our Leasing Programs were as follows: (in millions) Average Remaining Useful Life September 30, 2020 December 31, 2019 Leased wireless devices, gross 10 months $ 7,436 $ 1,139 Accumulated depreciation (1,648) (407) Leased wireless devices, net $ 5,788 $ 732
Schedule of Future Minimum Payments Expected to be Received	Future minimum payments expected to be received over the lease term related to leased wireless devices, which exclude optional residual buy-out amounts at the end of the lease term, are summarized below: (in millions) Expected Payments Twelve Months Ending September 30, 2021 $ 2,315 2022 156 Total $ 2,471

Restructuring Costs (Tables)

Restructuring Costs (Tables)	9 Months Ended
	Sep. 30, 2020
Restructuring and Related Activities [Abstract]
Restructuring Plan Expenses Incurred	The following table summarizes the expenses incurred in connection with our restructuring initiatives: Restructuring Expenses Incurred (in millions) Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Contract termination costs $ 56 $ 169 Severance costs 21 370 Network decommissioning 21 41 Total restructuring plan expenses $ 98 $ 580
Activity Related to Expenses Incurred and Cash Payments Made	The changes in the liabilities associated with our restructuring initiatives, including expenses incurred and cash payments, are as follows: (in millions) April 1, Expenses Incurred Cash Payments Adjustments for Non-Cash Items (1) September 30, 2020 Contract termination costs $ — $ 169 $ (74) $ (1) $ 94 Severance costs — 370 (174) (94) 102 Network decommissioning — 41 (20) (21) — Total $ — $ 580 $ (268) $ (116) $ 196

Additional Financial Informat_2

Additional Financial Information (Tables)	9 Months Ended
	Sep. 30, 2020
Supplemental Financial Statement Elements [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accounts payable and accrued liabilities are summarized as follows: (in millions) September 30, 2020 December 31, Accounts payable $ 3,862 $ 4,322 Payroll and related benefits 1,151 802 Property and other taxes, including payroll 1,386 682 Interest 760 227 Commissions 321 251 Toll and interconnect 179 156 Advertising 107 127 Other 623 179 Accounts payable and accrued liabilities $ 8,389 $ 6,746
Schedule of Significant Transactions with Affiliates	The following table summarizes the impact of significant transactions with DT or its affiliates included in Operating expenses in the Condensed Consolidated Statements of Comprehensive Income: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Discount related to roaming expenses $ — $ (1) $ (5) $ (3) Fees incurred for use of the T-Mobile brand 20 21 63 65 International long distance agreement 13 9 35 29
Schedule of Cash Flow, Supplemental Disclosures	The following table summarizes T-Mobile’s supplemental cash flow information: Three Months Ended September 30, Nine Months Ended September 30, (in millions) 2020 2019 2020 2019 Interest payments, net of amounts capitalized $ 940 $ 327 $ 1,889 $ 912 Operating lease payments 1,349 703 3,493 2,094 Income tax payments 63 5 118 77 Non-cash investing and financing activities Non-cash beneficial interest obtained in exchange for securitized receivables 1,535 1,734 4,634 4,862 Non-cash consideration for the acquisition of Sprint — — 33,533 — Decrease in accounts payable and accrued liabilities for purchases of property and equipment (216) (460) (555) (906) Leased devices transferred from inventory to property and equipment 599 298 2,352 612 Returned leased devices transferred from property and equipment to inventory (433) (65) (1,030) (189) Short-term debt assumed for financing of property and equipment — 475 38 775 Operating lease right-of-use assets obtained in exchange for lease obligations 11,833 989 13,046 3,083 Financing lease right-of-use assets obtained in exchange for lease obligations 219 395 912 943

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	Jul. 01, 2020USD ($)	Apr. 01, 2020USD ($)	Apr. 29, 2018shares	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2005USD ($)tower_site	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Device upgrade period						18 months
Revenues				$ 19,272	$ 11,061	$ 48,056	$ 33,120
Accumulated deficit				$ 6,586		$ 6,586				$ 8,833
Total imputed discount and allowance rate				7.80%		7.80%				7.00%
Postpaid revenues
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remaining contract duration (in years)						24 months
Revenues				$ 10,209	5,746	$ 26,055	16,852
Roaming and other service revenues | Reclassification
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues					$ 130		$ 364
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remaining contract duration (in years)						1 year
Minimum | Wireline Revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remaining contract duration (in years)						24 months
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remaining contract duration (in years)						9 years
Maximum | Wireline Revenue
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remaining contract duration (in years)						36 months
Maximum | EIP Securitization Arrangement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equipment installment plan, maximum payment term						24 months
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses									$ (91)
Deferred tax assets									24
Accumulated deficit									$ 67
DISH
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Initial term of leaseback								10 years
Renewal option term								5 years
Sprint
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of communications towers | tower_site								6,600
Term of lease-out								32 years
Upfront proceeds received								$ 1,200
Prepaid Business | T-Mobile and Sprint | DISH
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Payments for asset acquisition	$ 1,400
Sprint
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Exchange ratio (in shares) | shares			0.10256
Exchange ratio (in shares) | shares			9.75
Total term of agreement		30 years
Deferred tax assets		$ 1,000
Sprint | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Agreements with educational and certain non-profit institutions, term		5 years
Sprint | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Agreements with educational and certain non-profit institutions, term		10 years

Business Combination - Narrativ

Business Combination - Narrative (Details) $ / shares in Units, subscriber in Millions

Jul. 01, 2020USD ($)

Apr. 01, 2020USD ($)subscribershares

Feb. 20, 2020$ / sharesshares

May 18, 2018USD ($)

Apr. 29, 2018shares

Nov. 05, 2020USD ($)

Sep. 30, 2020USD ($)

Sep. 30, 2019USD ($)

Sep. 30, 2018USD ($)

Sep. 30, 2020USD ($)

Sep. 30, 2019USD ($)

Apr. 09, 2020USD ($)

Dec. 31, 2019USD ($)

Jan. 01, 2019USD ($)

Business Acquisition [Line Items]

Goodwill

$ 10,906,000,000

$ 10,906,000,000

$ 1,930,000,000

Restructuring liability

$ 0

196,000,000

196,000,000

Payments of consent fees

$ 0

$ 0

$ 109,000,000

$ 0

Subsequent Event | Settled Litigation

Business Acquisition [Line Items]

Settlement to resolve FCC's investigation

$ 200,000,000

DISH | T-Mobile and Sprint | Prepaid Business

Business Acquisition [Line Items]

Payments for asset acquisition

$ 1,400,000,000

Sprint

Business Acquisition [Line Items]

Exchange ratio (in shares) | shares

9.75

Exchange ratio (in shares) | shares

0.10256

Stock issued (in shares) | shares

373,396,310

Value of common stock provided in exchange for acquiree common stock

$ 31,328,000,000

Fully-diluted shares of combined company held by public stockholders (percent)

31.70%

31.70%

Goodwill

9,194,000,000

Goodwill expected to be tax deductible

0

Transaction costs

$ 8,000,000

$ 30,000,000

$ 192,000,000

$ 81,000,000

Value of contingent consideration

1,882,000,000

Contingent consideration, high end of range

7,300,000,000

Transaction costs assumed to have occurred

$ 550,000,000

Total revenue subsequent to Merger date

7,200,000,000

13,500,000,000

Operating income subsequent to Merger date

$ 897,000,000

$ 912,000,000

Spectrum licenses

45,400,000,000

Sprint | Customer relationships

Business Acquisition [Line Items]

Finite-lived, Fair Value (in millions)

$ 4,900,000,000

Weighted Average Useful Life (in years)

8 years

Sprint | Favorable lease (asset)

Business Acquisition [Line Items]

Finite-lived, Fair Value (in millions)

$ 790,000,000

Weighted Average Useful Life (in years)

18 years

Sprint | DT

Business Acquisition [Line Items]

Payments of consent fees

$ 7,000,000

Payments for requisite consents to DT

$ 13,000,000

Sprint | Shentel

Business Acquisition [Line Items]

Number of subscribers | subscriber

1.1

Sprint | Senior Notes

Business Acquisition [Line Items]

Payments for requisite consents to third-party note holders

$ 54,000,000

$ 95,000,000

Sprint | Secured Term Loan Facility

Business Acquisition [Line Items]

Financing commitment, amount

4,000,000,000

Sprint | Secured bridge loan facility due 2021

Business Acquisition [Line Items]

Financing commitment, amount

19,000,000,000

$ 19,000,000,000

Sprint | Secured and Unsecured Debt Financing

Business Acquisition [Line Items]

Payments of consent fees

$ 355,000,000

Sprint | SoftBank

Business Acquisition [Line Items]

Fully-diluted shares expected to be held immediately following merger (percent)

24.70%

24.70%

Sprint | DT

Business Acquisition [Line Items]

Fully-diluted shares expected to be held immediately following merger (percent)

43.60%

43.60%

Sprint | Common Stock

Business Acquisition [Line Items]

Exchange ratio (in shares) | shares

11

Sprint | Common Stock | SoftBank

Business Acquisition [Line Items]

Aggregate surrendered (in shares) | shares

48,751,557

Exchange ratio (in shares) | shares

11.31

Volume-weighted average price (in USD per share) | $ / shares

$ 150

Number of shares issued if threshold not met (in shares) | shares

0

Business Combination - Schedule

Business Combination - Schedule of Components of Consideration Transferred (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 01, 2020	Feb. 20, 2020	Apr. 29, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Payment received from selling shareholder				$ 0	$ (31)	$ (5,000)	$ (31)
Common stock, shares issued (in shares)				1,242,003,310		1,242,003,310			858,418,615
Common stock, shares outstanding (in shares)				1,240,458,618		1,240,458,618			856,905,400
Share price at closing (in USD per share)								$ 83.90
Sprint
Business Acquisition [Line Items]
Fair value of T-Mobile common stock issued to Sprint stockholders	$ 31,328
Fair value of T-Mobile replacement equity awards attributable to pre-combination service	323
Repayments of Sprint's debt (including accrued interest, prepayment penalties)	7,396
Value of contingent consideration	1,882
Payment received from selling shareholder	(102)
Total consideration exchanged	$ 40,827
Exchange ratio (in shares)			0.10256
Sprint | SoftBank | Common Stock Outstanding
Business Acquisition [Line Items]
Aggregate surrendered (in shares)		48,751,557

Business Combination - Schedu_2

Business Combination - Schedule of Amounts Recognized as of Acquisition Date (Details) - USD ($) $ in Millions	Apr. 01, 2020	Sep. 30, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Goodwill		$ 10,906	$ 1,930
Sprint
Business Acquisition [Line Items]
Cash and cash equivalents	$ 2,214
Accounts receivable	1,650
Equipment installment plan receivables	1,024
Inventory	658
Prepaid expenses	140
Assets held for sale	1,908
Other current assets	642
Property and equipment	17,230
Operating lease right-of-use assets	6,583
Financing lease right-of-use assets	291
Goodwill	9,194
Spectrum licenses	45,400
Other intangible assets	6,325
Equipment installment plan receivables due after one year, net	247
Other assets	541
Total assets acquired	94,047
Accounts payable and accrued liabilities	4,907
Short-term debt	2,760
Deferred revenue	508
Short-term operating lease liabilities	1,818
Short-term financing lease liabilities	8
Liabilities held for sale	475
Other current liabilities	650
Long-term debt	29,037
Tower obligations	950
Deferred tax liabilities	3,866
Operating lease liabilities	5,615
Financing lease liabilities	12
Other long-term liabilities	2,614
Total liabilities assumed	53,220
Total consideration exchanged	40,827
Restricted cash	$ 80

Business Combination - Schedu_3

Business Combination - Schedule of Additional Detail on Receivables Acquired in Merger (Details) $ in Billions	Apr. 01, 2020USD ($)
Accounts Receivable
Business Acquisition [Line Items]
Fair value of receivables acquired	$ 1.7
Gross amounts due	1.7
EIP Receivables
Business Acquisition [Line Items]
Fair value of receivables acquired	1.3
Gross amounts due	$ 1.6

Business Combination - Schedu_4

Business Combination - Schedule of Pro Forma Information (Details) - Sprint - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Business Acquisition [Line Items]
Total revenues	$ 19,269	$ 17,243	$ 54,342	$ 52,322
Income (loss) from continuing operations	1,359	451	2,455	(628)
Income from discontinued operations, net of tax	0	393	677	1,239
Net income	$ 1,359	$ 849	$ 3,132	$ 623

Receivables and Expected Cred_3

Receivables and Expected Credit Losses - EIP Receivables (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)classsegment	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio segments | segment	2
Customer classes | class	2
Total EIP Receivables, net of unamortized imputed discounts	$ 5,018		$ 4,582
Unamortized imputed discount	(248)		(299)
EIP receivables, net of unamortized imputed discount	4,770		4,283
Allowance for credit losses	(289)		(100)
Equipment installment plan receivables, net	4,481		4,183
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses		$ (91)
Equipment installment plan receivables, net of allowance for credit losses and imputed discount
Accounts, Notes, Loans and Financing Receivable [Line Items]
Equipment installment plan receivables, net	3,083		2,600
Equipment installment plan receivables due after one year, net of allowance for credit losses and imputed discount
Accounts, Notes, Loans and Financing Receivable [Line Items]
Equipment installment plan receivables, net	$ 1,398		$ 1,583

Receivables and Expected Cred_4

Receivables and Expected Credit Losses - Gross EIP Receivables by Credit Category (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	$ 4,770	$ 4,283
Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,554
Originated in 2019	780
Originated prior to 2019	196
Total EIP Receivables, net of unamortized imputed discounts	2,530
Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,487
Originated in 2019	682
Originated prior to 2019	71
Total EIP Receivables, net of unamortized imputed discounts	2,240
Current - 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	4,672
Current - 30 days past due | Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,540
Originated in 2019	766
Originated prior to 2019	193
Total EIP Receivables, net of unamortized imputed discounts	2,499
Current - 30 days past due | Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,453
Originated in 2019	654
Originated prior to 2019	66
Total EIP Receivables, net of unamortized imputed discounts	2,173
31 - 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	51
31 - 60 days past due | Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	9
Originated in 2019	8
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	18
31 - 60 days past due | Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	19
Originated in 2019	13
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	33
61 - 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	18
61 - 90 days past due | Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	2
Originated in 2019	2
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	5
61 - 90 days past due | Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	7
Originated in 2019	5
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	13
More than 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	29
More than 90 days past due | Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	3
Originated in 2019	4
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	8
More than 90 days past due | Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	8
Originated in 2019	10
Originated prior to 2019	3
Total EIP Receivables, net of unamortized imputed discounts	$ 21

Receivables and Expected Cred_5

Receivables and Expected Credit Losses - Unamortized Imputed Discount and Allowance for Credit Losses (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 460	$ 516	$ 516
Bad debt expense	489	218
Write-offs, net of recoveries	(244)	(242)
Change in imputed discount on short-term and long-term EIP receivables	60	91
Impact on the imputed discount from sales of EIP receivables	(111)	(127)
Allowance for credit losses and imputed discount, end of period	745	456	460
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	91
Allowance for credit losses and imputed discount, end of period			91
Accounts Receivable Allowance
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	61	67	67
Bad debt expense	261	51
Write-offs, net of recoveries	(114)	(57)
Allowance for credit losses and imputed discount, end of period	208	61	61
Accounts Receivable Allowance | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 0
Allowance for credit losses and imputed discount, end of period			$ 0
EIP Receivables Allowance
Financing Receivable, Allowance for Credit Loss [Line Items]
Weighted average effective imputed interest rate (percentage)	7.60%		8.80%
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 399	449	$ 449
Bad debt expense	228	167
Write-offs, net of recoveries	(130)	(185)
Change in imputed discount on short-term and long-term EIP receivables	60	91
Impact on the imputed discount from sales of EIP receivables	(111)	(127)
Allowance for credit losses and imputed discount, end of period	537	$ 395	399
EIP Receivables Allowance | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 91
Allowance for credit losses and imputed discount, end of period			$ 91

Sales of Certain Receivables -

Sales of Certain Receivables - Sales of Service Receivables (Details) - USD ($)	Sep. 30, 2020	Apr. 01, 2020	Dec. 31, 2019	Dec. 31, 2014
Variable Interest Entity [Line Items]
Other current assets	$ 2,889,000,000		$ 1,972,000,000
Accounts payable and accrued liabilities	8,389,000,000		6,746,000,000
Other current liabilities	1,817,000,000		1,673,000,000
Factoring Arrangement | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Revolving receivables facility, maximum borrowing capacity				$ 950,000,000
Revolving receivables facility, outstanding borrowings	828,000,000		924,000,000
Other current assets	386,000,000		350,000,000
Accounts payable and accrued liabilities	65,000,000		25,000,000
Other current liabilities	$ 371,000,000		$ 342,000,000
Sprint | Accounts receivable facility
Variable Interest Entity [Line Items]
Total amount outstanding		$ 2,300,000,000

Sales of Certain Receivables _2

Sales of Certain Receivables - Sales of EIP Receivables (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Dec. 31, 2015
Variable Interest Entity [Line Items]
Other current assets	$ 2,889,000,000	$ 1,972,000,000
Other assets	2,519,000,000	1,891,000,000
EIP Securitization Arrangement
Variable Interest Entity [Line Items]
Revolving receivables facility, maximum borrowing capacity	1,300,000,000	1,300,000,000	$ 1,300,000,000
Other current assets	353,000,000	344,000,000
Other assets	109,000,000	89,000,000
Other long-term liabilities	$ 8,000,000	$ 18,000,000

Sales of Certain Receivables _3

Sales of Certain Receivables - Sales of Receivables and Continuing Involvement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Other current assets	$ 2,889		$ 2,889		$ 1,972
Other long-term assets	2,519		2,519		1,891
Accounts payable and accrued liabilities	8,389		8,389		6,746
Other current liabilities	1,817		1,817		1,673
Other long-term liabilities	3,577		3,577		954
Of which:
(Gains) losses from sales of receivables	(18)	$ 28	37	$ 91
Factoring and EIP Securitization Arrangement | Variable Interest Entity, Primary Beneficiary
Of which:
Maximum exposure to loss, Factoring VIE	1,100		1,100
Factoring and EIP Securitization Arrangement | Variable Interest Entity, Primary Beneficiary
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Derecognized net service receivables and EIP receivables	2,535		2,535		2,584
Other current assets	739		739		694
Carrying amounts of deferred purchase price assets	846		846		781
Other long-term assets	109		109		89
Accounts payable and accrued liabilities	65		65		25
Other current liabilities	371		371		342
Other long-term liabilities	8		8		18
Net cash proceeds since inception			1,845		1,944
Of which:
Change in net cash proceeds during the year-to-date period			(99)		65
Net cash proceeds funded by reinvested collections			1,944		1,879
(Gains) losses from sales of receivables	(18)	$ 28	37	$ 91
Factoring and EIP Securitization Arrangement | Other current assets - of which, deferred purchase price | Variable Interest Entity, Primary Beneficiary
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Carrying amounts of deferred purchase price assets	737		737		692
Factoring and EIP Securitization Arrangement | Other long-term assets - of which, deferred purchase price | Variable Interest Entity, Primary Beneficiary
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Carrying amounts of deferred purchase price assets	$ 109		$ 109		$ 89

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	$ (40,276)		$ (40,276)		$ (33,118)
Property and equipment, net	38,567		38,567		21,984
Depreciation expense	3,800	$ 1,700	9,200	$ 4,800
Depreciation expense for lease devices	1,000	108	2,100	417
Capitalized interest	108	$ 118	339	$ 361
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment	236		236		0
Buildings and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	3,872		3,872		2,587
Wireless communications systems
Property, Plant and Equipment [Line Items]
Property, plant and equipment	45,666		45,666		34,353
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	1,750		1,750		1,345
Capitalized software
Property, Plant and Equipment [Line Items]
Property, plant and equipment	15,703		$ 15,703		12,705
Leased wireless devices
Property, Plant and Equipment [Line Items]
Useful life (in years)			10 months
Property, plant and equipment	7,436		$ 7,436		1,139
Accumulated depreciation and amortization	(1,648)		(1,648)		(407)
Property and equipment, net	5,788		5,788		732
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 4,180		$ 4,180		$ 2,973
Maximum | Buildings and equipment
Property, Plant and Equipment [Line Items]
Useful life (in years)			40 years
Maximum | Wireless communications systems
Property, Plant and Equipment [Line Items]
Useful life (in years)			20 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)			12 years
Maximum | Capitalized software
Property, Plant and Equipment [Line Items]
Useful life (in years)			10 years
Maximum | Leased wireless devices
Property, Plant and Equipment [Line Items]
Useful life (in years)			19 months

Property and Equipment - Asset

Property and Equipment - Asset Retirement Obligation (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning of year		$ 659	$ 609	$ 609
Fair value of liabilities acquired through Merger		1,062		0
Liabilities incurred		9		35
Liabilities settled		(16)		(2)
Accretion expense		37		32
Changes in estimated cash flows		0		(15)
Asset retirement obligations, end of period		1,751		659
Asset retirement costs capitalized, net		965		159
Non-cash impairment related to capitalized software development costs	$ 0	200	$ 0
Other long-term liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning of year		659
Asset retirement obligations, end of period		$ 1,751		$ 659

Goodwill, Spectrum License Tr_3

Goodwill, Spectrum License Transactions and Other Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Historical goodwill, net of accumulated impairment losses of $10,766		$ 1,901
Beginning balance	$ 1,930
Accumulated impairment losses	(10,985)	(10,766)
Layer3 goodwill impairment	(218)
Ending balance	10,906	1,930
Layer3 TV
Goodwill [Roll Forward]
Goodwill from acquisition		$ 29
Sprint
Goodwill [Roll Forward]
Goodwill from acquisition	$ 9,194

Goodwill, Spectrum License Tr_4

Goodwill, Spectrum License Transactions and Other Intangible Assets - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2020	Apr. 01, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 10,906		$ 1,930
Sprint
Goodwill [Line Items]
Goodwill		$ 9,194

Goodwill, Spectrum License Tr_5

Goodwill, Spectrum License Transactions and Other Intangible Assets - Schedule of Fair Value of Intangible Assets Acquired in Merger (Details) - Sprint $ in Millions	Apr. 01, 2020USD ($)
Finite-Lived Intangible Assets [Line Items]
Total intangible assets acquired	$ 51,725
Tradenames
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	2 years
Finite-lived, Fair Value (in millions)	$ 207
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	8 years
Finite-lived, Fair Value (in millions)	$ 4,900
Favorable spectrum leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	18 years
Finite-lived, Fair Value (in millions)	$ 790
Patent rights
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	7 years
Finite-lived, Fair Value (in millions)	$ 51
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	7 years
Finite-lived, Fair Value (in millions)	$ 377
Favorable lease (asset)
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	18 years
Finite-lived, Fair Value (in millions)	$ 790
Unfavorable spectrum leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	19 years
Finite-lived, Fair Value (in millions)	$ 197
Spectrum Licenses
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived, Fair Value (in millions)	$ 45,400
Fixed period	15 years

Goodwill, Spectrum License Tr_6

Goodwill, Spectrum License Transactions and Other Intangible Assets - Spectrum Licenses (Details) $ in Millions	Apr. 08, 2020USD ($)	Apr. 30, 2020USD ($)	Mar. 31, 2020USD ($)license	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Oct. 31, 2019USD ($)
Indefinite-lived Intangible Assets [Roll Forward]
Purchase of spectrum licenses				$ 13	$ 827	$ 863
Licensing Agreements
Indefinite-lived Intangible Assets [Roll Forward]
Beginning balance					36,465
Spectrum license acquisitions					1,006
Costs to clear spectrum					20
Ending balance					82,891
Licensing Agreements | Auction 103
Indefinite-lived Intangible Assets [Roll Forward]
Number of licenses | license			2,384
Purchase of spectrum licenses	$ 698		$ 873
Asset purchase deposit							$ 82
Incentive payments			59
Down payment			$ 93
Licensing Agreements | Auction 103 | Sprint
Indefinite-lived Intangible Assets [Roll Forward]
Number of licenses | license			127
Sprint | Licensing Agreements
Indefinite-lived Intangible Assets [Roll Forward]
Spectrum license acquisitions					$ 45,400
Sprint | Licensing Agreements | 800 MHz, 1.9 GHz and 2.5 GHz
Indefinite-lived Intangible Assets [Roll Forward]
Purchase of spectrum licenses		$ 45,400

Goodwill, Spectrum License Tr_7

Goodwill, Spectrum License Transactions and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment			$ 218
Gross Amount	$ 7,866		7,866		$ 1,527
Accumulated Amortization	(2,206)		(2,206)		(1,412)
Net Amount	5,660		5,660		115
Amortization expense for intangible assets	383	$ 18	794	$ 53
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2021	1,318		1,318
2022	1,040		1,040
2023	866		866
2024	709		709
2025	551		551
Thereafter	1,176		1,176
Net Amount	5,660		5,660		115
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	6,004		6,004		1,104
Accumulated Amortization	(1,681)		(1,681)		(1,104)
Net Amount	4,323		4,323		0
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Net Amount	4,323		$ 4,323		0
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life (in years)			8 years
Tradenames and patents
Finite-Lived Intangible Assets [Line Items]
Gross Amount	595		$ 595		323
Accumulated Amortization	(364)		(364)		(258)
Net Amount	231		231		65
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Net Amount	231		$ 231		65
Tradenames and patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life (in years)			19 years
Favorable spectrum leases
Finite-Lived Intangible Assets [Line Items]
Gross Amount	790		$ 790		0
Accumulated Amortization	(23)		(23)		0
Net Amount	767		767		0
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Net Amount	767		$ 767		0
Favorable spectrum leases | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life (in years)			27 years
Other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	477		$ 477		100
Accumulated Amortization	(138)		(138)		(50)
Net Amount	339		339		50
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Net Amount	$ 339		$ 339		$ 50
Other | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets, useful life (in years)			10 years

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	Jun. 24, 2020	Apr. 09, 2020	Apr. 06, 2020	Oct. 31, 2018
Derivative [Line Items]
Net collateral transfers to certain derivative counterparties		$ (580,000,000)	$ (632,000,000)
Accumulated other comprehensive loss	$ 1,621,000,000		868,000,000	$ 1,621,000,000
Principal Issuances	46,000,000,000			46,000,000,000
Amount amortized from AOCI into Interest expense	44,000,000			83,000,000
Amount expected to be amortized from AOCI into interest expense over next 12 months				185,000,000
Guarantee liabilities	45,000,000		62,000,000	45,000,000
Total EIP Receivables, net of unamortized imputed discounts	5,018,000,000		4,582,000,000	5,018,000,000
Level 3 | Fair Value
Derivative [Line Items]
Carrying amounts of deferred purchase price assets	846,000,000		781,000,000	846,000,000
Senior Notes
Derivative [Line Items]
Principal Issuances					$ 4,000,000,000	$ 19,000,000,000
Equipment installment plan receivables, net of allowance for credit losses and imputed discount
Derivative [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	2,900,000,000			2,900,000,000
3.500% Senior Secured Notes due 2025 | Senior Notes
Derivative [Line Items]
Principal Issuances	3,000,000,000			3,000,000,000
Interest rate, stated percentage						3.50%
4.500% Senior Secured Notes due 2050 | Senior Notes
Derivative [Line Items]
Principal Issuances	$ 3,000,000,000			$ 3,000,000,000
Interest rate, stated percentage						4.50%
Interest Rate Contract
Derivative [Line Items]
Derivative liabilities							$ 2,300,000,000
Cash-collateralized							$ 1,200,000,000
Interest Rate Contract | Cash Flow Hedging
Derivative [Line Items]
Aggregate notional amount								$ 9,600,000,000
Fair value of derivative instrument			$ 1,200,000,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Short-term Investments and Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Vendor Financing Arrangement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	$ 312	$ 25
Level 1 | Carrying Amount | Secured Term Loan Facility | Third Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	3,890	0
Level 1 | Carrying Amount | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	30,078	10,958
Level 1 | Carrying Amount | Senior Notes | Third Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	27,778	0
Level 1 | Fair Value | Secured Term Loan Facility | Third Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	3,990	0
Level 1 | Fair Value | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	31,906	11,479
Level 1 | Fair Value | Senior Notes | Third Party
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	31,105	0
Level 2 | Carrying Amount | Secured Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	0	4,000
Level 2 | Carrying Amount | Senior Notes | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	4,711	9,986
Level 2 | Fair Value | Secured Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	0	4,000
Level 2 | Fair Value | Senior Notes | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 4,981	$ 10,366

Debt - Debt Balances and Activi

Debt - Debt Balances and Activity (Details) - USD ($)	Apr. 09, 2020	Apr. 01, 2020	May 18, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 24, 2020
Debt Balances and Activity [Roll Forward]
Long-term debt, beginning balance						$ 10,958,000,000
Proceeds from Issuances and Borrowings				$ 0	$ 0	18,743,000,000	$ 0
Proceeds from Issuances and Borrowings						45,433,000,000
Assumed Debt				0	475,000,000	38,000,000	775,000,000
Note Redemptions				(4,665,000,000)		(4,665,000,000)
Repayments				0	0	(18,929,000,000)	0
Repayments				(5,678,000,000)	0	(16,207,000,000)	(600,000,000)
Long-term debt, ending balance				58,345,000,000		58,345,000,000
Repayments of short-term debt				0	$ 0	18,929,000,000	$ 0
Principal Issuances				46,000,000,000		46,000,000,000
Senior Notes
Debt Balances and Activity [Roll Forward]
Proceeds from Issuances and Borrowings	$ 18,800,000,000
Principal Issuances	$ 19,000,000,000							$ 4,000,000,000
Sprint
Debt Balances and Activity [Roll Forward]
Total debt, ending balance				27,155,000,000		27,155,000,000
Principal Issuances				24,904,000,000		24,904,000,000
Sprint | Senior Notes
Debt Balances and Activity [Roll Forward]
Payments for requisite consents to third-party note holders		$ 54,000,000	$ 95,000,000
Total Debt
Debt Balances and Activity [Roll Forward]
Total debt, beginning balance						24,969,000,000
Proceeds from Issuances and Borrowings						45,525,000,000
Assumed Debt						31,797,000,000
Note Redemptions				(30,689,000,000)		(30,689,000,000)
Repayments						(4,665,000,000)
Reclassifications						0
Other						(168,000,000)
Total debt, ending balance				66,769,000,000		66,769,000,000
Vendor Financing Arrangement
Debt Balances and Activity [Roll Forward]
Principal Issuances		200,000,000
Affiliates
Debt Balances and Activity [Roll Forward]
Note Redemptions				(30,950,000,000)		(30,950,000,000)
Third Party | Total Debt
Debt Balances and Activity [Roll Forward]
Total debt to third parties, beginning balance						10,983,000,000
Proceeds from Issuances and Borrowings						45,538,000,000
Assumed Debt						31,797,000,000
Note Redemptions				(21,413,000,000)		(21,413,000,000)
Repayments						(4,665,000,000)
Reclassifications						0
Other						(182,000,000)
Total debt to third parties, ending balance				62,058,000,000		62,058,000,000
DT | Sprint
Debt Balances and Activity [Roll Forward]
Payments for requisite consents to DT		(13,000,000)
DT | Affiliates | Sprint | Senior Notes
Debt Balances and Activity [Roll Forward]
Proceeds from Issuances and Borrowings		$ 4,000,000,000
Short-term Debt | Affiliates
Debt Balances and Activity [Roll Forward]
Short-term debt to affiliates, beginning balance						0
Proceeds from Issuances and Borrowings						0
Assumed Debt						0
Note Redemptions				(3,235,000,000)		(3,235,000,000)
Repayments						0
Reclassifications						3,231,000,000
Other						4,000,000
Short-term debt to affiliates, ending balance				0		0
Short-term Debt | Third Party
Debt Balances and Activity [Roll Forward]
Short-term debt, beginning balance						25,000,000
Proceeds from Issuances and Borrowings						18,943,000,000
Assumed Debt						2,760,000,000
Note Redemptions				(21,413,000,000)		(21,413,000,000)
Repayments						(2,355,000,000)
Reclassifications						5,696,000,000
Other						57,000,000
Short-term debt, ending balance				3,713,000,000		3,713,000,000
Repayments of short-term debt						2,355,000,000
Long-term debt | Affiliates
Debt Balances and Activity [Roll Forward]
Long-term debt to affiliates, beginning balance						13,986,000,000
Assumed Debt						0
Note Redemptions				(6,041,000,000)		(6,041,000,000)
Repayments						0
Reclassifications						(3,231,000,000)
Other						10,000,000
Long-term debt to affiliates, ending balance				4,711,000,000		4,711,000,000
Payments for requisite consents to DT						(13,000,000)
Long-term debt | Third Party
Debt Balances and Activity [Roll Forward]
Long-term debt, beginning balance						10,958,000,000
Proceeds from Issuances and Borrowings						26,595,000,000
Assumed Debt						29,037,000,000
Note Redemptions				0		0
Repayments						(2,310,000,000)
Reclassifications						(5,696,000,000)
Other						(239,000,000)
Long-term debt, ending balance				$ 58,345,000,000		$ 58,345,000,000

Debt - Issuances and Borrowings

Debt - Issuances and Borrowings (Details) - USD ($)	Apr. 09, 2020	Sep. 30, 2020	Jun. 24, 2020
Debt Instrument [Line Items]
Principal Issuances		$ 46,000,000,000
Discounts and Issuance Costs		567,000,000
Net Proceeds from Issuance of Long-Term Debt		45,433,000,000
Senior Notes
Debt Instrument [Line Items]
Principal Issuances	$ 19,000,000,000		$ 4,000,000,000
Net Proceeds from Issuance of Long-Term Debt	$ 18,800,000,000
3.500% Senior Secured Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	3.50%
Principal Issuances		3,000,000,000
Discounts and Issuance Costs		12,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 2,988,000,000
3.750% Senior Secured Notes due 2027 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		3.75%
Principal Issuances		$ 4,000,000,000
Discounts and Issuance Costs		17,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 3,983,000,000
3.875% Senior Secured Notes due 2030 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		3.875%
Principal Issuances		$ 7,000,000,000
Discounts and Issuance Costs		78,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 6,922,000,000
4.375% Senior Secured Notes due 2040 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		4.375%
Principal Issuances		$ 2,000,000,000
Discounts and Issuance Costs		47,000,000
Net Proceeds from Issuance of Long-Term Debt		1,953,000,000
4.500% Senior Secured Notes due 2050 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	4.50%
Principal Issuances		3,000,000,000
Discounts and Issuance Costs		24,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 2,976,000,000
1.500% Senior Secured Notes due 2026 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		1.50%
Principal Issuances		$ 1,000,000,000
Discounts and Issuance Costs		5,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 995,000,000
2.050% Senior Secured Notes due 2028 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		2.05%
Principal Issuances		$ 1,250,000,000
Discounts and Issuance Costs		8,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 1,242,000,000
2.550% Senior Secured Notes due 2031 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		2.55%
Principal Issuances		$ 1,750,000,000
Discounts and Issuance Costs		12,000,000
Net Proceeds from Issuance of Long-Term Debt		1,738,000,000
Total of Senior Secured Notes issued | Senior Notes
Debt Instrument [Line Items]
Principal Issuances		23,000,000,000
Discounts and Issuance Costs		203,000,000
Net Proceeds from Issuance of Long-Term Debt		22,797,000,000
Secured bridge loan facility due 2021 | Bridge Loan
Debt Instrument [Line Items]
Principal Issuances		19,000,000,000
Discounts and Issuance Costs		257,000,000
Net Proceeds from Issuance of Long-Term Debt		18,743,000,000
Secured term loan facility due 2027
Debt Instrument [Line Items]
Principal Issuances		4,000,000,000
Discounts and Issuance Costs		107,000,000
Net Proceeds from Issuance of Long-Term Debt		3,893,000,000
Total of Secured loan facilities issued
Debt Instrument [Line Items]
Principal Issuances		23,000,000,000
Discounts and Issuance Costs		364,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 22,636,000,000

Debt - Commitment Letter and Se

Debt - Commitment Letter and Senior Secured Notes (Details)

Oct. 30, 2020USD ($)tower_site

Oct. 28, 2020USD ($)

Oct. 09, 2020USD ($)

Apr. 09, 2020USD ($)

Apr. 01, 2020USD ($)

Sep. 30, 2020USD ($)

Sep. 30, 2019USD ($)

Sep. 30, 2018USD ($)

Sep. 30, 2020USD ($)

Sep. 30, 2019USD ($)

Oct. 06, 2020USD ($)

Sep. 16, 2020USD ($)

Jun. 24, 2020USD ($)

Mar. 31, 2018USD ($)

Debt Instrument [Line Items]

Principal Issuances

$ 46,000,000,000

$ 46,000,000,000

Payments of consent fees

$ 0

$ 0

109,000,000

$ 0

Net Proceeds from Issuance of Long-Term Debt

$ 45,433,000,000

Subsequent Event

Debt Instrument [Line Items]

Net Proceeds from Issuance of Long-Term Debt

$ 4,600,000,000

$ 4,000,000,000

Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 19,000,000,000

$ 4,000,000,000

Net Proceeds from Issuance of Long-Term Debt

$ 18,800,000,000

Senior Notes | Sprint

Debt Instrument [Line Items]

Principal Issuances

$ 3,900,000,000

Line of Credit | Revolving Credit Facility

Debt Instrument [Line Items]

Financing commitment, amount

$ 5,500,000,000

5.300% Senior Notes due 2021 | Senior Notes | Affiliates

Debt Instrument [Line Items]

Interest rate, stated percentage

5.30%

5.30%

Guaranteed Notes due 2028 | Sprint

Debt Instrument [Line Items]

Interest rate, stated percentage

7.25%

Principal amount outstanding

$ 1,000,000,000

3.500% Senior Secured Notes due 2025 | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 3,000,000,000

$ 3,000,000,000

Interest rate, stated percentage

3.50%

Net Proceeds from Issuance of Long-Term Debt

2,988,000,000

4.500% Senior Secured Notes due 2050 | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

3,000,000,000

3,000,000,000

Interest rate, stated percentage

4.50%

Net Proceeds from Issuance of Long-Term Debt

2,976,000,000

1.500% Senior Secured Notes due 2026 | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 1,000,000,000

$ 1,000,000,000

Interest rate, stated percentage

1.50%

1.50%

Net Proceeds from Issuance of Long-Term Debt

$ 995,000,000

2.550% Senior Secured Notes due 2031 | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 1,750,000,000

$ 1,750,000,000

Interest rate, stated percentage

2.55%

2.55%

Net Proceeds from Issuance of Long-Term Debt

$ 1,738,000,000

2.550% Senior Secured Notes due 2031 | Senior Notes | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 1,000,000,000

$ 750,000,000

Interest rate, stated percentage

2.25%

2.55%

2.050% Senior Secured Notes due 2028 | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 1,250,000,000

$ 1,250,000,000

Interest rate, stated percentage

2.05%

2.05%

Net Proceeds from Issuance of Long-Term Debt

$ 1,242,000,000

2.050% Senior Secured Notes due 2028 | Senior Notes | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 500,000,000

Interest rate, stated percentage

2.05%

3.000% Senior Secured Notes due 2041 | Senior Notes | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 1,250,000,000

$ 1,250,000,000

Interest rate, stated percentage

3.00%

3.00%

3.300% Senior Secured Notes due 2051 | Senior Notes | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 1,500,000,000

$ 1,500,000,000

Interest rate, stated percentage

3.30%

3.30%

3.600% Senior Secured Notes due 2060 | Senior Notes | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 1,000,000,000

Interest rate, stated percentage

3.60%

Senior Secured Term Loan Commitment | Subsequent Event

Debt Instrument [Line Items]

Principal Issuances

$ 5,000,000,000

Number of extension options | tower_site

1

Extension term

6 months

Senior Secured Term Loan Commitment | LIBOR | Subsequent Event

Debt Instrument [Line Items]

Variable rate

1.25%

Sprint

Debt Instrument [Line Items]

Principal Issuances

$ 24,904,000,000

24,904,000,000

Sprint | DT

Debt Instrument [Line Items]

Payments of consent fees

$ 7,000,000

Sprint | DT | Senior Notes | Affiliates

Debt Instrument [Line Items]

Indebtedness to affiliates

4,000,000,000

Sprint | Secured Debt Financing

Debt Instrument [Line Items]

Financing commitment, amount

27,000,000,000

Proceeds from Lines of Credit

22,600,000,000

Sprint | Secured Revolving Credit Facility

Debt Instrument [Line Items]

Financing commitment, amount

$ 4,000,000,000

Sprint | Secured Revolving Credit Facility | LIBOR | Maximum

Debt Instrument [Line Items]

Variable rate

1.25%

Sprint | Secured Revolving Credit Facility | LIBOR | Minimum

Debt Instrument [Line Items]

Variable rate

1.00%

Sprint | Secured Term Loan Facility

Debt Instrument [Line Items]

Financing commitment, amount

$ 4,000,000,000

Net leverage ratio

0.75

Sprint | Secured Term Loan Facility | DT

Debt Instrument [Line Items]

Repayment of debt

$ 4,000,000,000

Sprint | Secured Term Loan Facility | LIBOR

Debt Instrument [Line Items]

Variable rate

3.00%

Sprint | Secured bridge loan facility due 2021

Debt Instrument [Line Items]

Financing commitment, amount

$ 19,000,000,000

$ 19,000,000,000

Sprint | Secured bridge loan facility due 2021 | LIBOR

Debt Instrument [Line Items]

Variable rate

1.25%

Sprint | New Credit Agreement

Debt Instrument [Line Items]

Financial maintenance covenant

3.3

Sprint | 5.300% Senior Notes due 2021 | DT | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 2,000,000,000

Interest rate, stated percentage

5.30%

Sprint | 6.000% Senior Notes due 2024 | DT | Senior Notes

Debt Instrument [Line Items]

Principal Issuances

$ 2,000,000,000

Interest rate, stated percentage

6.00%

Sprint | Secured Term Loan due 2024

Debt Instrument [Line Items]

Principal amount outstanding

$ 5,900,000,000

Sprint | Accounts receivable facility

Debt Instrument [Line Items]

Principal Issuances

$ 0

$ 0

Total amount outstanding

2,300,000,000

Sprint | Secured and Unsecured Debt Financing

Debt Instrument [Line Items]

Payments of consent fees

$ 355,000,000

Debt - Debt Assumed (Details)

Debt - Debt Assumed (Details) - USD ($)	Sep. 30, 2020	Aug. 15, 2020	Jun. 24, 2020	Apr. 09, 2020	Apr. 01, 2020
Debt Instrument [Line Items]
Principal Outstanding	$ 46,000,000,000
Sprint
Debt Instrument [Line Items]
Fair value					$ 31,797,000,000
Principal Outstanding	24,904,000,000
Carrying Value	27,155,000,000
Accounts receivable facility | Sprint
Debt Instrument [Line Items]
Fair value					2,310,000,000
Principal Outstanding	0
Carrying Value	0
Other debt | Sprint
Debt Instrument [Line Items]
Fair value					$ 464,000,000
Principal Outstanding	336,000,000
Carrying Value	312,000,000
Senior Notes
Debt Instrument [Line Items]
Principal Outstanding			$ 4,000,000,000	$ 19,000,000,000
Senior Notes | Senior Notes due 2021, 7.250% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					725.00%
Fair value					$ 2,324,000,000
Principal Outstanding	2,250,000,000
Carrying Value	2,300,000,000
Senior Notes | Senior Notes due 2023, 7.875% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					787.50%
Fair value					$ 4,682,000,000
Principal Outstanding	4,250,000,000
Carrying Value	4,624,000,000
Senior Notes | Senior Notes due 2024, 7.125% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					712.50%
Fair value					$ 2,746,000,000
Principal Outstanding	2,500,000,000
Carrying Value	2,720,000,000
Senior Notes | Senior Notes due 2025, 7.625% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					762.50%
Fair value					$ 1,677,000,000
Principal Outstanding	1,500,000,000
Carrying Value	1,661,000,000
Senior Notes | Senior Notes due 2026, 7.625% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					762.50%
Fair value					$ 1,701,000,000
Principal Outstanding	1,500,000,000
Carrying Value	$ 1,687,000,000
Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Interest rate, stated percentage	3.36%
Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					336.00%
Fair value					$ 1,310,000,000
Principal Outstanding	$ 875,000,000				$ 3,500,000,000
Carrying Value	874,000,000
Senior Notes | Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					473.80%
Fair value					$ 2,153,000,000
Principal Outstanding	2,100,000,000
Carrying Value	2,148,000,000
Senior Notes | Senior Secured Series 2018-1 A-2 Notes due 2028, 5.152% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					515.20%
Fair value					$ 1,960,000,000
Principal Outstanding	1,838,000,000				$ 1,800,000,000
Carrying Value	1,953,000,000
Senior Notes | Senior Notes due 2020, 7.000%
Debt Instrument [Line Items]
Interest rate, stated percentage		700.00%			700.00%
Senior Notes | Senior Notes due 2020, 7.000% | Sprint
Debt Instrument [Line Items]
Fair value					$ 1,510,000,000
Principal Outstanding	0
Carrying Value	0
Senior Notes | Senior Notes due 2021, 11.500%
Debt Instrument [Line Items]
Interest rate, stated percentage					11.50%
Senior Notes | Senior Notes due 2021, 11.500% | Sprint
Debt Instrument [Line Items]
Fair value					$ 1,105,000,000
Principal Outstanding	1,000,000,000
Carrying Value	1,074,000,000
Senior Notes | Senior Notes due 2022, 6.000% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					600.00%
Fair value					$ 2,372,000,000
Principal Outstanding	2,280,000,000
Carrying Value	2,355,000,000
Senior Notes | Senior Notes due 2028, 6.875% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					687.50%
Fair value					$ 2,834,000,000
Principal Outstanding	2,475,000,000
Carrying Value	2,817,000,000
Senior Notes | Senior Notes due 2032, 8.750% | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage					875.00%
Fair value					$ 2,649,000,000
Principal Outstanding	2,000,000,000
Carrying Value	$ 2,630,000,000

Debt - Redemptions and Repaymen

Debt - Redemptions and Repayments (Details) - USD ($)	Sep. 01, 2020	Jul. 04, 2020	Apr. 09, 2020	Sep. 30, 2020	Aug. 15, 2020	Apr. 01, 2020
Debt Instrument [Line Items]
Principal Amount				$ 4,665,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				0
Affiliates
Debt Instrument [Line Items]
Principal Amount				30,950,000,000
Write off of Premiums, Discounts and Issuance Costs				261,000,000
Other				11,000,000
Bridge Loan
Debt Instrument [Line Items]
Principal Amount				19,000,000,000
Write off of Premiums, Discounts and Issuance Costs				251,000,000
Other				(47,000,000)
Secured bridge loan facility due 2021
Debt Instrument [Line Items]
Other			$ 71,000,000
Secured bridge loan facility due 2021 | Sprint
Debt Instrument [Line Items]
Financing commitment, amount			$ 19,000,000,000			$ 19,000,000,000
Secured bridge loan facility due 2021 | Bridge Loan
Debt Instrument [Line Items]
Principal Amount				19,000,000,000
Write off of Premiums, Discounts and Issuance Costs				251,000,000
Other				$ (47,000,000)
Redemption Price (as a percent)				100.128%
6.500% Senior Notes due 2024 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		6.50%		6.50%
Principal Amount		$ 1,000,000,000		$ 1,000,000,000
Write off of Premiums, Discounts and Issuance Costs				12,000,000
Other				$ 22,000,000
Redemption Price (as a percent)		102.167%		102.167%
Redemption premium		$ 22,000,000
Write-off of issuance costs		$ 12,000,000
6.375% Senior Notes due 2025 | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	637.50%			6.375%
Principal Amount	$ 1,700,000,000			$ 1,700,000,000
Write off of Premiums, Discounts and Issuance Costs				24,000,000
Other				$ 36,000,000
Redemption Price (as a percent)	102.125%			102.125%
Redemption premium	$ 36,000,000
Write-off of issuance costs	$ 24,000,000
Total of Secured bridge loan facility and Senior Notes to third parties redeemed
Debt Instrument [Line Items]
Principal Amount				$ 21,700,000,000
Write off of Premiums, Discounts and Issuance Costs				287,000,000
Other				$ 11,000,000
5.300% Senior Notes due 2021 | Affiliates | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage				5.30%
Principal Amount				$ 2,000,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				$ 0
Redemption Price (as a percent)				100.00%
6.000% Senior Notes due 2024 | Affiliates | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage				6.00%
Principal Amount				$ 1,350,000,000
Write off of Premiums, Discounts and Issuance Costs				(26,000,000)
Other				$ 0
Redemption Price (as a percent)				100.00%
6.000% Senior Notes due 2024 | Affiliates | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage				6.00%
Principal Amount				$ 650,000,000
Write off of Premiums, Discounts and Issuance Costs				(15,000,000)
Other				$ 0
Redemption Price (as a percent)				100.00%
Incremental term loan facility to affiliates due 2022 | Affiliates
Debt Instrument [Line Items]
Principal Amount				$ 2,000,000,000		2,000,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				$ 0
Redemption Price (as a percent)				100.00%
Incremental term loan facility to affiliates due 2024 | Affiliates
Debt Instrument [Line Items]
Principal Amount				$ 2,000,000,000		$ 2,000,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				$ 0
Redemption Price (as a percent)				100.00%
5.125% Senior Notes due 2021 | Affiliates | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage		5.125%		5.125%
Principal Amount		$ 1,250,000,000		$ 1,250,000,000
Write off of Premiums, Discounts and Issuance Costs				15,000,000
Other				$ 0
Redemption Price (as a percent)		100.00%		100.00%
Write-off of issuance costs		$ 15,000,000
Total of Senior Notes and Incremental term loan facilities to affiliates redeemed | Affiliates
Debt Instrument [Line Items]
Principal Amount				$ 9,250,000,000
Write off of Premiums, Discounts and Issuance Costs				(26,000,000)
Other				0
Accounts receivable facility
Debt Instrument [Line Items]
Principal Amount				2,310,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				$ 0
Redemption Price (as a percent)				100.00%
Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360% | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage				3.36%
Principal Amount				$ 438,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				0
Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360% | Senior Notes | Sprint
Debt Instrument [Line Items]
Interest rate, stated percentage						336.00%
Senior Notes due 2020, 7.000% | Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage					700.00%	700.00%
Principal Amount				1,500,000,000	$ 1,500,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				0
Secured term loan facility due 2027
Debt Instrument [Line Items]
Principal Amount				10,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				0
Other debt
Debt Instrument [Line Items]
Principal Amount				407,000,000
Write off of Premiums, Discounts and Issuance Costs				0
Other				$ 0

Debt - Financing Matters Agreem

Debt - Financing Matters Agreement, Senior Notes to Affiliates, Spectrum Financing and Consents on Debt to Third-Parties (Details)	Apr. 01, 2020USD ($)	May 18, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 24, 2020USD ($)	Apr. 09, 2020USD ($)	Dec. 31, 2019USD ($)	Mar. 31, 2018USD ($)note
Debt Instrument [Line Items]
Payments of consent fees			$ 0	$ 0				$ 109,000,000	$ 0
Principal Amount			4,665,000,000					4,665,000,000
Principal Issuances			46,000,000,000					46,000,000,000
Payments for third party bank fees			4,876,000,000	$ 3,498,000,000				14,168,000,000	$ 10,483,000,000
Short-term debt			3,713,000,000					3,713,000,000				$ 25,000,000
Affiliates
Debt Instrument [Line Items]
Principal Amount			30,950,000,000					30,950,000,000
Long-term debt | Affiliates
Debt Instrument [Line Items]
Repayment of debt								0
Principal Amount			6,041,000,000					6,041,000,000
Payments for requisite consents to DT								13,000,000
Incremental term loan facility to affiliates due 2022 | Affiliates
Debt Instrument [Line Items]
Principal Amount	$ 2,000,000,000		2,000,000,000					$ 2,000,000,000
Redemption Price (as a percent)								100.00%
Incremental term loan facility to affiliates due 2024 | Affiliates
Debt Instrument [Line Items]
Principal Amount	2,000,000,000		2,000,000,000					$ 2,000,000,000
Redemption Price (as a percent)								100.00%
Senior Notes
Debt Instrument [Line Items]
Principal Issuances										$ 4,000,000,000	$ 19,000,000,000
Senior Notes | Sprint
Debt Instrument [Line Items]
Principal Issuances													$ 3,900,000,000
Senior Notes | 5.300% Senior Notes due 2021 | Affiliates
Debt Instrument [Line Items]
Principal Amount			$ 2,000,000,000					$ 2,000,000,000
Interest rate, stated percentage			5.30%					5.30%
Redemption Price (as a percent)								100.00%
Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Principal Amount			$ 438,000,000					$ 438,000,000
Interest rate, stated percentage			3.36%					3.36%
Spectrum Financing SPEs
Debt Instrument [Line Items]
Lease payments (per month)	165,000,000
Sprint
Debt Instrument [Line Items]
Principal Issuances			$ 24,904,000,000					$ 24,904,000,000
Notes issued and outstanding under Existing Sprint Spectrum Program (not exceed)		$ 7,000,000,000
Total outstanding obligation			4,800,000,000					4,800,000,000
Sprint | Credit Facilities
Debt Instrument [Line Items]
Financing commitment, amount		$ 9,000,000,000
Secured indebtedness, limit, percentage		150.00%
Secured debt to cash flow		2
Sprint | Secured Term Loan Facility
Debt Instrument [Line Items]
Financing commitment, amount	4,000,000,000
Sprint | Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738%
Debt Instrument [Line Items]
Short-term debt			263,000,000					263,000,000
Sprint | Senior Notes
Debt Instrument [Line Items]
Payments for third party bank fees							$ 6,000,000
Payments for requisite consents to third-party note holders	54,000,000	$ 95,000,000
Sprint | Senior Notes | Long-term debt
Debt Instrument [Line Items]
Payments of consent fees					$ 17,000,000
Sprint | Senior Notes | Existing Sprint Spectrum Notes
Debt Instrument [Line Items]
Payments for requisite consents to third-party note holders	41,000,000
Sprint | Senior Notes | Existing Sprint Spectrum Notes | Long-term debt
Debt Instrument [Line Items]
Payments of consent fees							$ 14,000,000
Sprint | Senior Notes | Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Principal Issuances	$ 3,500,000,000		875,000,000					875,000,000
Interest rate, stated percentage	336.00%
Securitization program	$ 7,000,000,000
Payable term	5 years
Schedule principal repayments			438,000,000
Principal amount outstanding			875,000,000					875,000,000
Number of senior secured notes | note													2
Sprint | Senior Notes | Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738%
Debt Instrument [Line Items]
Principal Issuances			2,100,000,000					2,100,000,000
Interest rate, stated percentage	473.80%
Sprint | Senior Notes | Senior Secured Series 2018-1 A-2 Notes due 2028, 5.152%
Debt Instrument [Line Items]
Principal Issuances	$ 1,800,000,000		$ 1,838,000,000					$ 1,838,000,000
Interest rate, stated percentage	515.20%
Sprint | DT
Debt Instrument [Line Items]
Payments of consent fees						$ 7,000,000
Payments for requisite consents to DT	$ 13,000,000
Sprint | DT | Secured Term Loan Facility
Debt Instrument [Line Items]
Repayment of debt	4,000,000,000
Sprint | DT | Senior Notes | Affiliates
Debt Instrument [Line Items]
Indebtedness to affiliates	4,000,000,000
Sprint | DT | Senior Notes | 5.300% Senior Notes due 2021
Debt Instrument [Line Items]
Principal Issuances	$ 2,000,000,000
Interest rate, stated percentage	5.30%
Sprint | DT | Senior Notes | 6.000% Senior Notes due 2024
Debt Instrument [Line Items]
Principal Issuances	$ 2,000,000,000
Interest rate, stated percentage	6.00%
Sprint | DT | Senior Notes | 5.125% Senior Notes Due 2025
Debt Instrument [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	5.125%
Sprint | DT | Senior Notes | 5.375% Senior Notes Due 2027
Debt Instrument [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	5.375%

Debt - Standby Letters of Credi

Debt - Standby Letters of Credit (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Letters of credit, amount outstanding	$ 546	$ 113

Tower Obligations - Narrative (

Tower Obligations - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)tower_site	Mar. 31, 2020USD ($)tower_site	Sep. 30, 2020USD ($)tower_site	Dec. 31, 2012USD ($)tower_site	Apr. 01, 2020USD ($)
Sale Leaseback Transaction [Line Items]
Lease liabilities	$ 30,316		$ 30,316
Crown Castle International Corp.
Sale Leaseback Transaction [Line Items]
Managed sites | tower_site	900		900
Lease liabilities	$ 285		$ 285
Minimum
Sale Leaseback Transaction [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)	5 years		5 years
Maximum
Sale Leaseback Transaction [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)	10 years		10 years
Tower Transaction
Sale Leaseback Transaction [Line Items]
Number of wireless communications tower sites sold | tower_site				7,100
Lessee leasing arrangements, operating leases, term of contract (years)				10 years
Sale leaseback transaction, fixed-price purchase options				$ 2,000
Interest rate on tower obligations	6.00%			8.00%
Weighted average remaining term			6 years
Tower Transaction | Crown Castle International Corp.
Sale Leaseback Transaction [Line Items]
Property subject to failed sale leaseback transaction, number of units | tower_site		6,400
Remaining term of lease		17 years
Fixed-price purchase option on leased or subleased sites		$ 2,300
Fixed-price purchase option on lease or subleased sites, exercisable period		1 year
Days prior to expiration of agreement		120 days
Property and equipment at fair value					$ 1,500
Tower obligations					$ 1,100
Tower Transaction | Minimum
Sale Leaseback Transaction [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)				23 years
Tower Transaction | Maximum
Sale Leaseback Transaction [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)				37 years

Tower Obligations - Sale Leaseb

Tower Obligations - Sale Leaseback Transaction (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Property and equipment, net
Sale Leaseback Transaction [Line Items]
Failed sale-leasebacks	$ 1,544	$ 198
Failed Sale Leaseback Transaction, Tower Obligations
Sale Leaseback Transaction [Line Items]
Failed sale-leasebacks	$ 3,079	$ 2,236

Tower Obligations - Future Mini

Tower Obligations - Future Minimum Payments (Details) $ in Millions	Sep. 30, 2020USD ($)
Leases [Abstract]
Tower obligation payments, due 2021	$ 393
Tower obligation payments, due 2022 and 2023	738
Tower obligation payment, due 2024 and 2025	591
Tower obligation payments due thereafter	$ 694

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 19,272	$ 11,061	$ 48,056	$ 33,120
Postpaid phone revenues
Disaggregation of Revenue [Line Items]
Revenues	9,532	5,400	24,450	15,870
Postpaid other revenues
Disaggregation of Revenue [Line Items]
Revenues	677	346	1,605	982
Postpaid service revenues
Disaggregation of Revenue [Line Items]
Revenues	10,209	5,746	26,055	16,852
Wireless service revenues | Sprint
Disaggregation of Revenue [Line Items]
Revenues	213		424
Equipment revenues from the lease of mobile communication devices
Disaggregation of Revenue [Line Items]
Revenues	$ 1,350	$ 142	$ 2,936	$ 446

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Apr. 01, 2020	Dec. 31, 2019
Change in Contract with Customer, Asset and Liability [Abstract]
Contract Assets	$ 243		$ 243			$ 63
Contract Liabilities	783		783			560
Change in contract assets included in other current assets			180
Change in contracts liabilities included in deferred revenue			223
Current portion of contract assets	187		187			50
Amounts included in the beginning of year contract liability balance	5	$ 39	543	$ 642
Disaggregation of Revenue [Line Items]
Contract Assets	243		243			63
Contract Liabilities	$ 783		$ 783			$ 560
Sprint
Change in Contract with Customer, Asset and Liability [Abstract]
Contract Assets					$ 154
Contract Liabilities					252
Disaggregation of Revenue [Line Items]
Contract Assets					154
Contract Liabilities					$ 252

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Remaining Performance Obligations, Branded Postpaid Contracts (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Apr. 01, 2020
Postpaid service revenues
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,300
Remaining contract duration (in years)	24 months
Promotional bill credits | Sprint
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation		$ 1,000
Service performance obligations | Sprint
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3,300	4,800
Lease performance obligation | Sprint
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,800	$ 2,600
Remaining contract duration (in years)	18 months
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining contract duration (in years)	1 year
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining contract duration (in years)	9 years

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 382
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,300
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,400
Remaining performance obligation, expected timing of satisfaction, period

Revenue from Contracts with C_7

Revenue from Contracts with Customers - Contract Costs (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Apr. 02, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Deferred incremental costs to obtain contracts	$ 1,000,000,000		$ 1,000,000,000			$ 906,000,000
Average amortization period, deferred contract costs (in months)	24 months		24 months
Amortization of deferred costs	$ 221,000,000	$ 162,000,000	$ 631,000,000	$ 415,000,000
Contract Liabilities	783,000,000		783,000,000			$ 560,000,000
Impairment losses recognized on deferred contract cost assets	$ 0	$ 0	$ 0	$ 0
Sprint
Disaggregation of Revenue [Line Items]
Contract Liabilities					$ 1,700,000,000

Employee Compensation and Ben_3

Employee Compensation and Benefit Plans - Narrative (Details)	9 Months Ended
	Sep. 30, 2020shares
Restricted Stock and Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Performance Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
2013 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance (in shares)	101,000,000
Number of shares available for future grants (in shares)	25,000,000

Employee Compensation and Ben_4

Employee Compensation and Benefit Plans - Schedule of Stock-based Compensation Expense and Related Income Tax Benefits (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 161	$ 126	$ 558	$ 366
Income tax benefit related to stock-based compensation	$ 34	$ 25	$ 105	$ 70
Restricted Stock Units and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per stock award granted (in USD per share)	$ 114.52	$ 77.41	$ 97.28	$ 73.18
Unrecognized compensation expense	$ 670	$ 631	$ 670	$ 631
Weighted average period to be recognized (years)	1 year 10 months 24 days	1 year 9 months 18 days	1 year 10 months 24 days	1 year 9 months 18 days
Fair value of stock awards vested	$ 264	$ 14	$ 1,079	$ 356

Employee Compensation and Ben_5

Employee Compensation and Benefit Plans - Stock Awards (Details) - Long-Term Stock Incentive Program - Common Stock Outstanding	Apr. 22, 2020shares
T-Mobile
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares of T-Mobile common stock issuable upon exercise or settlement	7,043,843
Shares of common stock available for issuance	12,420,945
Additional shares of T-Mobile common stock subject to awards granted	5,839,436
Sprint
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Number of shares registered	25,304,224

Employee Compensation and Ben_6

Employee Compensation and Benefit Plans - Schedule of Restricted Stock and Unit Awards and Performance Restricted Stock Units Activity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Taxes paid related to net share settlement of stock awards	$ 72	$ 4	$ 351	$ 108
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Share payout percentage			0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Share payout percentage			200.00%
Restricted Stock and Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested, beginning (in shares)			10,503,211
Assumed through acquisition (in shares)			1,852,527
Granted (in shares)			5,598,737
Vested (in shares)			(6,151,759)
Forfeited (in shares)			(861,098)
Nonvested, ending (in shares)	10,941,618		10,941,618		10,503,211
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested, beginning (in USD per share)			$ 67.31
Assumed through acquisition (in USD per share)			83.90
Granted (in USD per share)			95.56
Vested (in USD per share)			69.74
Forfeited (in USD per share)			84.14
Nonvested, ending (in USD per share)	$ 81.90		$ 81.90		$ 67.31
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Nonvested, Weighted Average Remaining Contractual Term, beginning (in years)			1 year		10 months 24 days
Nonvested, Weighted Average Remaining Contractual Term, ending (in years)			1 year		10 months 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Nonvested, Aggregate Intrinsic Value, beginning	$ 1,251		$ 1,251		$ 824
Nonvested, Aggregate Intrinsic Value, ending	$ 1,251		$ 1,251		$ 824
Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested, beginning (in shares)			3,803,539
Assumed through acquisition (in shares)			3,535,384
Granted (in shares)			1,962,547
Vested (in shares)			(5,120,598)
Forfeited (in shares)			(136,359)
Nonvested, ending (in shares)	4,044,513		4,044,513		3,803,539
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Nonvested, beginning (in USD per share)			$ 69.78
Assumed through acquisition (in USD per share)			83.90
Granted (in USD per share)			105.49
Vested (in USD per share)			76.32
Forfeited (in USD per share)			83.90
Nonvested, ending (in USD per share)	$ 83.69		$ 83.69		$ 69.78
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Nonvested, Weighted Average Remaining Contractual Term, beginning (in years)			10 months 24 days		1 year
Nonvested, Weighted Average Remaining Contractual Term, ending (in years)			10 months 24 days		1 year
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Nonvested, Aggregate Intrinsic Value, beginning	$ 465		$ 465		$ 300
Nonvested, Aggregate Intrinsic Value, ending	$ 465		$ 465		$ 300
Restricted Stock Units and Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted (in USD per share)	$ 114.52	$ 77.41	$ 97.28	$ 73.18
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value [Abstract]
Shares paid for tax withholding for share based compensation (in shares)	648,872	53,349	3,703,906	1,474,011

Employee Compensation and Ben_7

Employee Compensation and Benefit Plans - Employee Stock Purchase Plan (Details) - shares	Jan. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Contribution percentage (up to)		15.00%		15.00%
Stock purchase discount percentage				15.00%
ESPP, offering period				6 months
Number of securities remaining available for future sale and issuance under ESPP (in shares)				4,253,858
Aggregate number of shares, annual increase (in shares)				5,000,000
Additional shares of common stock (in shares)	5,000,000
Common Stock
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Number of shares issued under ESPP (in shares)		897,732	955,849	2,144,036	2,091,650

Employee Compensation and Ben_8

Employee Compensation and Benefit Plans - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Grant-date fair value of share-based incentive compensation awards			$ 163
Predecessor Plans
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding and exercisable, beginning (in shares)			194,942
Assumed through acquisition (in shares)			1,635,518
Exercised (in shares)			(794,853)
Expired/canceled (in shares)			(4,296)
Outstanding and exercisable, ending (in shares)	1,031,311		1,031,311		194,942
Exercisable (in shares)	1,029,731		1,029,731
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding and exercisable, beginning (usd per share)			$ 13.80
Assumed through acquisition (usd per share)			33.37
Exercised (usd per share)			52.27
Expired/canceled (usd per share)			41.82
Outstanding and exercisable, ending (usd per share)	$ 52.51		52.51		$ 13.80
Exercisable (usd per share)	$ 52.55		$ 52.55
Weighted Average Remaining Contractual Term (Years), Outstanding			4 years 1 month 6 days		2 years 10 months 24 days
Weighted Average Remaining Contractual Term (Years), Exercisable			4 years 1 month 6 days
Proceeds from exercise of stock options	$ 27	$ 0	$ 42	$ 1

Employee Compensation and Ben_9

Employee Compensation and Benefit Plans - Pension Plan (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Apr. 01, 2020
Share-based Payment Arrangement [Abstract]
Interest on projected benefit obligations	$ 18	$ 35
Expected return on pension plan assets	(15)	(30)
Net pension expense	3	5
Postretirement benefit plan assets	1,200	1,200	$ 1,200
Projected benefit obligations	2,100	2,100	2,100
Underfunded plan	900	900	$ 900
Contributions to benefit plan	26	42
Expected contributions to the Plan through end of fiscal year	$ 16	$ 16

Employee Compensation and Be_10

Employee Compensation and Benefit Plans - Employee Retirement Savings Plan (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Employer retirement savings plan, matching contributions	$ 49	$ 24	$ 128	$ 88

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) $ in Millions	Jul. 01, 2020USD ($)
Prepaid Business | T-Mobile and Sprint | DISH
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for asset acquisition	$ 1,400
Prepaid Business | T-Mobile and Sprint | DISH | Transition Services Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transition period (up to)	3 years
Prepaid Business | T-Mobile and Sprint | DISH | Master Network Services Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transition period (up to)	7 years
Prepaid Business | T-Mobile and Sprint | DISH | EIP Receivables
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for asset acquisition	$ 162
Prepaid Business | DISH | EIP Receivables
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Participation interest	100.00%
Prepaid Business, Divested Net Assets | T-Mobile and Sprint | DISH
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for asset acquisition	$ 1,200
Spectrum Licenses | T-Mobile and Sprint | DISH
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for asset acquisition	$ 3,600
Additional lease period	2 years
Fee liability for failure to deliver the purchase price	$ 72
Decommissioned Towers and Retail Locations | DISH | T-Mobile and Sprint
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Option period (up to)	5 years

Discontinued Operations - Compo

Discontinued Operations - Components of Discontinued Operations from Merger Date (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations	$ 0	$ 0	$ 320	$ 0
Net cash provided by operating activities from the Prepaid Business			611
Discontinued Operations, Disposed of by Sale | Prepaid Transaction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues			1,270
Selling, general and administrative			314
Total operating expenses			838
Pretax income from discontinued operations			432
Income tax expense			(112)
Income from discontinued operations			320
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Prepaid revenues
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues			973
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Roaming and other services revenue
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues			27
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Service
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues			1,000
Cost of services and sales			25
Discontinued Operations, Disposed of by Sale | Prepaid Transaction | Equipment revenues
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Service revenues			270
Cost of services and sales			$ 499

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Apr. 01, 2020
Income Tax Contingency [Line Items]
Income tax expense	$ (407)	$ (325)	$ (715)	$ (921)
Federal statutory income tax rate	24.50%	27.10%	26.40%	25.30%
Sprint
Income Tax Contingency [Line Items]
Deferred tax assets					$ 1,000
Uncertain tax benefit reserves					$ 540

SoftBank Equity Transaction - N

SoftBank Equity Transaction - Narrative (Details) $ / shares in Units, $ in Millions	Jun. 26, 2020$ / sharesshares	Jun. 22, 2020USD ($)$ / sharesshares	Sep. 30, 2020USD ($)shares	Aug. 03, 2020shares
Valuation, Income Approach
Subsidiary, Sale of Stock [Line Items]
Fair value of each call option, estimate | $			$ 1,000
Marcelo Claure
Subsidiary, Sale of Stock [Line Items]
Shares sold (in shares)			5,000,000
Additional paid-in capital
Subsidiary, Sale of Stock [Line Items]
Payment received to facilitate SoftBank Monetization | $			$ 304
Rights Offering
Subsidiary, Sale of Stock [Line Items]
Price per share in public offering (in USD per share) | $ / shares	$ 103
Public Equity Offering
Subsidiary, Sale of Stock [Line Items]
Payment received to facilitate SoftBank Monetization | $		$ 304
Shares sold (in shares)	154,100,000
Public Equity Offering | Third-party trust
Subsidiary, Sale of Stock [Line Items]
Shares sold (in shares)	19,400,000
Public Equity Offering | Additional paid-in capital
Subsidiary, Sale of Stock [Line Items]
Payment received, net of tax | $		$ 230
Rights Offering | Warrants and Rights Subject to Mandatory Redemption
Subsidiary, Sale of Stock [Line Items]
Option to purchase common stock (in shares) (up to)				19,750,000
Conversion rate for option to purchase common stock	0.05
SoftBank
Subsidiary, Sale of Stock [Line Items]
Shares of common stock held by SoftBank		198,000,000
Percentage of stock held			8.60%
SoftBank | Direct and Indirect Call Option | DT
Subsidiary, Sale of Stock [Line Items]
Option to purchase shares (in shares) (up to)			101,500,000
SoftBank | Fixed-Price Call Option | DT
Subsidiary, Sale of Stock [Line Items]
Option to purchase shares (in shares) (up to)		44,900,000
Option to purchase shares (in USD per share) | $ / shares		$ 101.46
SoftBank | Floating-Price Call Option | DT
Subsidiary, Sale of Stock [Line Items]
Option to purchase shares (in shares) (up to)		56,600,000
DT
Subsidiary, Sale of Stock [Line Items]
Percentage of stock held			43.40%
Voting control, percentage			52.40%
Other Stockholders
Subsidiary, Sale of Stock [Line Items]
Percentage of stock held			48.00%

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Income from continuing operations	$ 1,253	$ 870	$ 1,994	$ 2,717
Income from discontinued operations, net of tax	0	0	320	0
Net income	$ 1,253	$ 870	$ 2,314	$ 2,717
Weighted average shares outstanding - basic (in shares)	1,238,450,665	854,578,241	1,111,511,964	853,391,370
Effect of dilutive securities:
Outstanding stock options and unvested stock awards (in shares)	11,348,075	8,112,510	10,528,564	9,463,284
Weighted average shares outstanding - diluted (in shares)	1,249,798,740	862,690,751	1,122,040,528	862,854,654
Basic earnings per share:
Continuing operations (in USD per share)	$ 1.01	$ 1.02	$ 1.79	$ 3.18
Discontinued operations (in USD per share)	0	0	0.29	0
Basic (in USD per share)	1.01	1.02	2.08	3.18
Earnings Per Share, Diluted [Abstract]
Continuing operations (in USD per share)	1	1.01	1.78	3.15
Discontinued operations (in USD per share)	0	0	0.28	0
Diluted (in USD per share)	$ 1	$ 1.01	$ 2.06	$ 3.15
Outstanding stock options and unvested stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	54,485	241	30,469	30,314
SoftBank contingent consideration
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	48,751,557	0	32,738,272	0

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Apr. 01, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	2,000,000,000		2,000,000,000		2,000,000,000	2,000,000,000
SoftBank contingent consideration
Class of Stock [Line Items]
Potentially dilutive securities (in shares)	48,751,557	0	32,738,272	0
Mandatory Convertible Preferred Stock Series A
Class of Stock [Line Items]
Preferred shares authorized (in shares)	100,000,000		100,000,000
Preferred stock, par value (in USD per share)	$ 0.00001		$ 0.00001
Preferred shares outstanding (in shares)	0	0	0	0

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 14, 2020USD ($)tower_site	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 27,999		$ 27,999			$ 10,933
Lease liabilities	30,316		30,316
Interest payments for financing leases	19	$ 20	59	$ 61
Additional operating leases not yet commenced, payments due	$ 283		$ 283
Device upgrade period			18 months
American Tower
Lessee, Lease, Description [Line Items]
Number of licensed towers | tower_site					20,729
Operating lease right-of-use assets					$ 11,000
Lease liabilities					$ 11,000
Minimum
Lessee, Lease, Description [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)	5 years		5 years
Option to extend lease term			5 years
Lessee leasing arrangements, finance leases, term of contract	2 years		2 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee leasing arrangements, operating leases, term of contract (years)	10 years		10 years
Option to extend lease term			35 years
Lessee leasing arrangements, finance leases, term of contract	5 years		5 years

Leases - Schedule of Lease Expe

Leases - Schedule of Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease expense	$ 1,259	$ 657	$ 3,082	$ 1,893
Financing lease expense:
Amortization of right-of-use assets	183	146	508	376
Interest on lease liabilities	20	21	60	61
Total financing lease expense	203	167	568	437
Variable lease expense	106	62	239	185
Total lease expense	$ 1,568	$ 886	$ 3,889	$ 2,515

Leases - Schedule of Informatio

Leases - Schedule of Information Related to Lease Term and Discount Rate (Details)	Sep. 30, 2020
Weighted Average Remaining Lease Term (Years)
Operating leases	10 years
Financing leases	3 years
Weighted Average Discount Rate
Operating leases	4.00%
Financing leases	3.50%

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Operating and Finance Lease Maturities (Details) $ in Millions	Sep. 30, 2020USD ($)
Operating Leases
2021	$ 4,717
2022	4,361
2023	3,754
2024	3,301
2025	2,785
Thereafter	19,184
Total lease payments	38,102
Less: imputed interest	7,786
Total	30,316
Finance Leases
2021	1,100
2022	792
2023	426
2024	89
2025	61
Thereafter	72
Total lease payments	2,540
Less: imputed interest	117
Total	$ 2,423

Leases - Leased Wireless Device

Leases - Leased Wireless Devices (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Apr. 01, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (40,276)		$ (33,118)
Property and equipment, net	$ 38,567		21,984
Leased wireless devices
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 months
Property, plant and equipment	$ 7,436		1,139
Accumulated depreciation	(1,648)		(407)
Property and equipment, net	$ 5,788		$ 732
Leased wireless devices | Sprint
Property, Plant and Equipment [Line Items]
Property and equipment, net		$ 5,800

Leases - Schedule of Future M_2

Leases - Schedule of Future Minimum Payments Expected to be Received (under 842) (Details) $ in Millions	Sep. 30, 2020USD ($)
Leases [Abstract]
2021	$ 2,315
2022	156
Total	$ 2,471

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Nov. 05, 2020	Sep. 30, 2020
Operating Leased Assets [Line Items]
Purchase commitment, due 2021		$ 4,200
Purchase commitment, due 2022 and 2023		3,400
Purchase commitment, due 2024 and 2025		1,600
Purchase commitment, due thereafter		1,500
Lease and service credit commitment, due 2021		328
Lease and service credit commitment, due 2022 and 2023		698
Lease and service credit commitment, due 2024 and 2025		609
Lease and service credit commitment, due thereafter		5,100
Maximum remaining commitment		92
Merger commitment, due 2021		24
Merger commitment, due in 2022 and 2023		36
Merger commitment, due in 2024 and 2025		$ 13
Subsequent Event | Settled Litigation
Operating Leased Assets [Line Items]
Settlement to resolve FCC's investigation	$ 200
Minimum
Operating Leased Assets [Line Items]
Commitment term		15 years
Maximum
Operating Leased Assets [Line Items]
Commitment term		30 years

Restructuring Costs - Restructu

Restructuring Costs - Restructuring Plan Expenses Incurred (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 98	$ 580	$ 580
Contract termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	56	169	169
Severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	21	370	370
Network decommissioning
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 21	$ 41	$ 41

Restructuring Costs - Narrative

Restructuring Costs - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Restructuring and Related Activities [Abstract]
Amortization of the right-of-use assets on lease contracts	$ 80	$ 80

Restructuring Costs - Activity

Restructuring Costs - Activity Related to Expenses Incurred and Cash Payments Made (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2020
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		$ 0
Expenses Incurred	$ 98	580	$ 580
Cash Payments		(268)
Adjustments		(116)
Restructuring Reserve, Ending Balance	196	196	196
Contract termination costs
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0
Expenses Incurred	56	169	169
Cash Payments		(74)
Adjustments		(1)
Restructuring Reserve, Ending Balance	94	94	94
Severance costs
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0
Expenses Incurred	21	370	370
Cash Payments		(174)
Adjustments		(94)
Restructuring Reserve, Ending Balance	102	102	102
Network decommissioning
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0
Expenses Incurred	21	41	41
Cash Payments		(20)
Adjustments		(21)
Restructuring Reserve, Ending Balance	$ 0	$ 0	$ 0

Additional Financial Informat_3

Additional Financial Information - Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Supplemental Financial Statement Elements [Abstract]
Accounts payable	$ 3,862	$ 4,322
Payroll and related benefits	1,151	802
Property and other taxes, including payroll	1,386	682
Interest	760	227
Commissions	321	251
Toll and interconnect	179	156
Advertising	107	127
Other	623	179
Accounts payable and accrued liabilities	8,389	6,746
Accounts Payable and Accrued Liabilities
Accounts Payable and Accrued Liabilities [Line Items]
Outstanding checks	$ 240	$ 463

Additional Financial Informat_4

Additional Financial Information - Related Party Transactions (Details) - USD ($)	Apr. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jul. 04, 2020	Jun. 24, 2020	Apr. 09, 2020
Related Party Transaction [Line Items]
Principal Amount		$ 4,665,000,000		$ 4,665,000,000
Principal Issuances		46,000,000,000		46,000,000,000
Senior Notes
Related Party Transaction [Line Items]
Principal Issuances							$ 4,000,000,000	$ 19,000,000,000
Sprint
Related Party Transaction [Line Items]
Principal Issuances		24,904,000,000		24,904,000,000
DT | Sprint
Related Party Transaction [Line Items]
Payments for requisite consents to DT	$ 13,000,000
Affiliates
Related Party Transaction [Line Items]
Principal Amount		30,950,000,000		30,950,000,000
Discount related to roaming expenses		0	$ (1,000,000)	(5,000,000)	$ (3,000,000)
Fees incurred for use of the T-Mobile brand		20,000,000	21,000,000	63,000,000	65,000,000
International long distance agreement		13,000,000	9,000,000	35,000,000	29,000,000
Reimbursement of certain administrative expenses		2,000,000	$ 3,000,000	5,000,000	$ 8,000,000
Affiliates | DT | Sprint | Senior Notes
Related Party Transaction [Line Items]
Indebtedness to affiliates	4,000,000,000
Secured Term Loan Facility | DT | Sprint
Related Party Transaction [Line Items]
Repayments of Debt	4,000,000,000
Incremental term loan facility to affiliates due 2022 | Affiliates
Related Party Transaction [Line Items]
Principal Amount	2,000,000,000	2,000,000,000		2,000,000,000
Incremental term loan facility to affiliates due 2024 | Affiliates
Related Party Transaction [Line Items]
Principal Amount	2,000,000,000	2,000,000,000		2,000,000,000
5.300% Senior Notes due 2021 | DT | Sprint | Senior Notes
Related Party Transaction [Line Items]
Principal Issuances	$ 2,000,000,000
Interest rate, stated percentage	5.30%
5.300% Senior Notes due 2021 | Affiliates | Senior Notes
Related Party Transaction [Line Items]
Principal Amount		$ 2,000,000,000		$ 2,000,000,000
Interest rate, stated percentage		5.30%		5.30%
6.000% Senior Notes due 2024 | DT | Sprint | Senior Notes
Related Party Transaction [Line Items]
Principal Issuances	$ 2,000,000,000
Interest rate, stated percentage	6.00%
5.125% Senior Notes Due 2025 | DT | Sprint | Senior Notes
Related Party Transaction [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	5.125%
5.375% Senior Notes Due 2027 | DT | Sprint | Senior Notes
Related Party Transaction [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	5.375%
5.125% Senior Notes due 2021 | Affiliates | Senior Notes
Related Party Transaction [Line Items]
Principal Amount		$ 1,250,000,000		$ 1,250,000,000		$ 1,250,000,000
Interest rate, stated percentage		5.125%		5.125%		5.125%

Additional Financial Informat_5

Additional Financial Information - Additional Information (Details) - shares	9 Months Ended
	Sep. 30, 2020	Aug. 03, 2020
Warrants and Rights Subject to Mandatory Redemption | Rights Offering
Related Party Transaction [Line Items]
Option to purchase common stock (in shares) (up to)		19,750,000
DT
Related Party Transaction [Line Items]
Percentage of stock held	43.40%
Voting control, percentage	52.40%
SoftBank
Related Party Transaction [Line Items]
Percentage of stock held	8.60%
Other Stockholders
Related Party Transaction [Line Items]
Percentage of stock held	48.00%
DT | SoftBank | Direct and Indirect Call Option
Related Party Transaction [Line Items]
Option to purchase shares (in shares) (up to)	101,500,000

Additional Financial Informat_6

Additional Financial Information - Supplemental Consolidated Statements of Cash Flows Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transactions [Abstract]
Interest payments, net of amounts capitalized	$ 940	$ 327	$ 1,889	$ 912
Operating lease payments	1,349	703	3,493	2,094
Income tax payments	63	5	118	77
Non-cash investing and financing activities
Non-cash beneficial interest obtained in exchange for securitized receivables	1,535	1,734	4,634	4,862
Non-cash consideration for the acquisition of Sprint	0	0	33,533	0
Decrease in accounts payable and accrued liabilities for purchases of property and equipment	(216)	(460)	(555)	(906)
Leased devices transferred from inventory to property and equipment	599	298	2,352	612
Returned leased devices transferred from property and equipment to inventory	(433)	(65)	(1,030)	(189)
Short-term debt assumed for financing of property and equipment	0	475	38	775
Operating lease right-of-use assets obtained in exchange for lease obligations	11,833	989	13,046	3,083
Financing lease right-of-use assets obtained in exchange for lease obligations	$ 219	$ 395	$ 912	$ 943

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details)	Oct. 30, 2020USD ($)tower_site	Oct. 28, 2020USD ($)	Oct. 09, 2020USD ($)	Apr. 09, 2020USD ($)	Nov. 05, 2020USD ($)	Sep. 30, 2020USD ($)	Oct. 06, 2020USD ($)	Jun. 24, 2020USD ($)
Subsequent Event [Line Items]
Principal Issuances						$ 46,000,000,000
Net Proceeds from Issuance of Long-Term Debt						45,433,000,000
Senior Notes
Subsequent Event [Line Items]
Principal Issuances				$ 19,000,000,000				$ 4,000,000,000
Net Proceeds from Issuance of Long-Term Debt				$ 18,800,000,000
2.050% Senior Secured Notes due 2028 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances						$ 1,250,000,000
Interest rate, stated percentage						2.05%
Net Proceeds from Issuance of Long-Term Debt						$ 1,242,000,000
2.550% Senior Secured Notes due 2031 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances						$ 1,750,000,000
Interest rate, stated percentage						2.55%
Net Proceeds from Issuance of Long-Term Debt						$ 1,738,000,000
Subsequent Event
Subsequent Event [Line Items]
Net Proceeds from Issuance of Long-Term Debt		$ 4,600,000,000	$ 4,000,000,000
Subsequent Event | Settled Litigation
Subsequent Event [Line Items]
Settlement to resolve FCC's investigation					$ 200,000,000
Subsequent Event | 2.050% Senior Secured Notes due 2028 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances							$ 500,000,000
Interest rate, stated percentage							2.05%
Subsequent Event | 2.550% Senior Secured Notes due 2031 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances		$ 1,000,000,000					$ 750,000,000
Interest rate, stated percentage		2.25%					2.55%
Subsequent Event | 3.000% Senior Secured Notes due 2041 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances		$ 1,250,000,000					$ 1,250,000,000
Interest rate, stated percentage		3.00%					3.00%
Subsequent Event | 3.300% Senior Secured Notes due 2051 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances		$ 1,500,000,000					$ 1,500,000,000
Interest rate, stated percentage		3.30%					3.30%
Subsequent Event | 3.600% Senior Secured Notes due 2060 | Senior Notes
Subsequent Event [Line Items]
Principal Issuances		$ 1,000,000,000
Interest rate, stated percentage		3.60%
Subsequent Event | Senior Secured Term Loan Commitment
Subsequent Event [Line Items]
Principal Issuances	$ 5,000,000,000
Payable term	364 days
Number of extension options | tower_site	1
Extension term	6 months
Subsequent Event | Senior Secured Term Loan Commitment | LIBOR
Subsequent Event [Line Items]
Variable rate	1.25%