The components of property and equipment, excluding amounts transferred to held for sale, were as follows:


(in millions)	Useful Lives	December 31, 2025		December 31, 2024

Land		$	100	$	69
Buildings and equipment	Up to 30 years	4,521		4,377
Wireless communications systems	Up to 20 years	70,653		65,778
Leasehold improvements	Up to 10 years	2,750		2,588
Capitalized software	Up to 3 years	21,762		18,566
Leased wireless devices	Up to 16 months	30		145
Construction in progress	N/A	2,329		3,377
Accumulated depreciation and amortization		(63,812)		(56,367)

Property and equipment, net		$	38,333	$	38,533

Total depreciation and amortization expense relating to property and equipment and financing lease right-of-use assets was $12.6 billion, $12.1 billion and $12.0 billion for the years ended December 31, 2025, 2024 and 2023.

We capitalize interest associated with the acquisition or construction of certain property and equipment and spectrum intangible assets. We recognized capitalized interest of $43 million, $34 million and $104 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Asset retirement obligations are primarily for certain legal obligations to remediate leased property on which our network infrastructure and administrative assets are located.


(in millions)	Year Ended December 31, 2025		Year Ended December 31, 2024

Asset retirement obligations, beginning of year	$	1,535	$	1,716
Fair value of liabilities acquired from the UScellular Acquisition	182		—
Liabilities incurred	35		21
Liabilities settled	(46)		(307)
Accretion expense	73		69
Changes in estimated cash flows	—		36


Asset retirement obligations, end of period	$	1,779	$	1,535

Classified on the consolidated balance sheets as:

Other current liabilities	$	114	$	109
Other long-term liabilities	1,665		1,426

The corresponding assets, net of accumulated depreciation, related to asset retirement obligations were $561 million and $423 million as of December 31, 2025 and 2024, respectively.

In connection with our accelerated digital transformation initiatives, including streamlining our billing technology, we evaluated our billing system architecture strategy and concluded components of our billing system replacement plan and associated development will no longer serve our future needs. As a result, we recorded a non-cash impairment of $278 million related to capitalized software development costs during the year ended December 31, 2025, within Impairment expense on our Consolidated Statements of Comprehensive Income.