
	December 31,
	2023		2022
Furniture and fixtures and other	571		3,384
Leasehold improvements	19,167		18,428
Computer hardware and purchased software	5,741		110,338
Internally-developed software (1)	295,860		334,079
Total property, equipment and software, gross	321,339		466,229
Less: accumulated depreciation and amortization	(290,809)		(409,498)
Property, equipment and software, net	$	30,530	$	56,731

(1)The net carrying amount of internally-developed software was $28.4 million and $48.6 million as of December 31, 2023 and 2022.

We performed an assessment in the first, second, third and fourth quarters of 2023 and did not identify a triggering event that would have required us to test for impairment for such periods.

During the first quarter of 2022, we determined the impact to our business from the new variant of COVID-19 required us to evaluate our long-lived assets for impairment. Our interim quantitative assessment for the first quarter of 2022 did not identify any long-lived asset impairment.

During the second quarter of 2022, we determined a downward revision of our forecast required us to evaluate our long-lived assets for impairment. As a result of our interim quantitative assessment, we recognized long-lived asset impairment related to certain asset groups within our International reporting unit. See details in the table below.

During the fourth quarter of 2022, we determined a further downward revision of our forecast required us to evaluate our long-lived assets for impairment. As a result of our interim quantitative assessment, we recognized long-lived asset impairment related to certain asset groups within our International reporting unit. Additionally, during the fourth quarter of 2022, we determined that certain internally developed software was no longer in use. As a result, we recognized long-lived asset impairment related to internally developed software. See details in the table below.

During the third quarter of 2021, we recognized long-lived asset impairments for certain leasehold improvements under our 2020 Restructuring Plan. See details in the table below and Note 13, Restructuring and Related Charges, for more information.

In order to evaluate long-lived assets for impairment in 2022 and 2021, we compared the fair value our asset groups to their carrying value. In determining the fair values of our asset groups, we used the discounted cash flow method under the income approach that uses Level 3 inputs. The significant estimates used in the discounted cash flow models are the risk-adjusted discount rates; forecasted revenue, cost of revenue and operating expenses; forecasted capital expenditures and working capital needs; weighted-average cost of capital; rates of long-term growth; and income tax rates.

The following table summarizes impairment charges for property, equipment and software that are presented within Restructuring and related charges and Long-lived asset impairment on the Consolidated Statements of Operations for the years ended December 31, 2023, 2022 and 2021 (in thousands):


	Year Ended December 31,
	2023		2022		2021
Long-lived asset impairment:
North America	$	—	$	753	$	—
International	—		3,736		—
Long-lived asset impairment	—		4,489		—
Restructuring and related charges:
North America	—		—		602
International	—		—		268
Restructuring and related charges impairment	—		—		870
Total property, equipment and software impairment	$	—	$	4,489	$	870

The following table summarizes impairment for long-lived assets by asset type for the years ended December 31, 2023, 2022 and 2021 (in thousands):


	Year Ended December 31,
Long-Lived Asset Category	2023		2022		2021
Property, equipment and software, net
Leasehold improvements	—		1,747		870
Computer hardware	—		1,498		—
Internally-developed software	—		753		—
Other Property, equipment and software, net	—		491		—
Total	$	—	$	4,489	$	870

Depreciation and amortization expense on property, equipment and software is classified as follows in the accompanying Consolidated Statements of Operations for the years ended December 31, 2023, 2022 and 2021 (in thousands):


	Year Ended December 31,
	2023		2022		2021
Service cost of revenue	$	25,024	$	32,554	$	32,354
Product cost of revenue	—		—		378
Selling, general and administrative	18,377		21,616		31,193
Total	$	43,401	$	54,170	$	63,925

The above amounts include amortization of internally-developed software of $38.1 million, $44.2 million and $50.5 million for the years ended December 31, 2023, 2022 and 2021.