Property, plant, and equipment, net at December 31, 2024 and 2023 are as follows:




	Estimated	December 31,		December 31,
($ in millions)	Useful Lives	2024		2023

Land	N/A	$	241	$	243
Buildings and leasehold improvements	40 years		1,250		1,221
General support	5 to 15 years		591		427
Central office/electronic circuit equipment	5 to 8 years		3,226		2,467
Poles	30 years		1,074		915
Cable, fiber, and wire	15 to 27 years		9,921		7,718
Conduit	50 years		1,429		1,416
Materials and supplies			431		594
Construction work in progress			1,155		1,323
Property, plant, and equipment			19,318		16,324
Less: Accumulated depreciation			(3,640)		(2,391)
Property, plant, and equipment, net		$	15,678	$	13,933

Property, plant, and equipment includes approximately $246 million and $179 million of fixed assets recognized under finance leases as of December 31, 2024 and 2023, respectively.

As of December 31, 2024, our materials and supplies were $431 million, as compared to $594 million as of December 31, 2023. Components of this include fiber, network electronics, and customer premises equipment.

Beginning in the second half of 2023, Frontier negotiated payment terms with certain of our vendors, (referred to as vendor financing), which are excluded from capital expenditures and reported as financing activities on the statement of cash flows. As of December 31, 2024, our capital expenditures were $2,783 million. For the year ended December 31, 2024, our vendor financing payments were $463 million. As of December 31, 2024, there was $585 million, $8 million, and $24 million in “Accounts payable and accrued liabilities”, “Other current liabilities” and “Other liabilities”, respectively, for payables associated with capital expenditures, and $16 million included in “Other current liabilities” for vendor financing payables associated with capital expenditures. For the year ended December 31, 2024, we had capitalized interest of $49 million.

In 2024, we sold certain properties consisting of land and buildings for approximately $18 million. The aggregate carrying value of the properties was approximately $11 million, resulting in a gain on sale of $7 million.

In 2023, we had asset sales and transactions of $63 million, including approximately $47 million in net proceeds related to certain wireless towers. Approximately $19 million of the proceeds related to wireless towers that qualified as sales, included in investing cash flows, and the remaining $28 million in proceeds related to wireless towers that were subject to sale-leaseback agreements and included in financing cash flows. After taking these sales and transactions into account, along with our capital expenditures, our net capital activity was $3,148 million for the year ended December 31, 2023.

During 2022, we sold a property that was subject to leaseback, generating approximately $70 million in proceeds.

Depreciation expense is principally based on the composite group method. Depreciation expense was as follows:




	For the year ended		For the year ended		For the year ended
	December 31,		December 31,		December 31,
($ in millions)	2024		2023		2022

Depreciation expense	$	1,304	$	1,094	$	861

We adopted revised estimated remaining useful lives for certain plant assets as of October 1, 2024, as a result of an annual independent study of the estimated remaining useful lives of our plant assets, with an insignificant impact to depreciation expense.