	March 31, 2019			December 31, 2018
Computer equipment	$	27,428		$	27,294
Computer software		31,978			27,422
Furniture and fixtures		1,620			1,618
Leasehold improvements		1,244			1,256
Work in process (primarily software development costs)		599			4,584
Other		179			179
		63,048			62,353
Less accumulated depreciation		(45,360	)		(43,646	)
Property and equipment, net	$	17,688		$	18,707

Depreciation expense totaled $2.0 million and $1.9 million for the three months ended March 31, 2019 and 2018, respectively.

Property and equipment includes computer equipment and software held under finance leases of $8.4 million and $8.0 million as of March 31, 2019 and 2018, respectively. Accumulated depreciation of computer equipment and software held under finance leases amounted to $5.3 million and $3.0 million as of March 31, 2019 and 2018, respectively.

For the three months ended March 31, 2019 and 2018, the Company capitalized a total of $0.7 million, and $0.8 million of costs that occurred during the application development phase, related to the development of internal-use software. The Company capitalized a total of $0.3 million and $0.8 million of costs related to the development of software for sale or license for the three months ended March 31, 2019 and 2018 that occurred after technological feasibility had been achieved.

Amortization of software capitalized for internal use was $1.1 million and $1.1 million, for the three months ended March 31, 2019 and 2018, respectively and included in depreciation and amortization in the consolidated statement of operations. Amortization of software for sale or license for the three months ended March 31, 2019 and 2018 was not material.

Impairment charges related to software, previously capitalized for internal use, for the three months ended March 31, 2019 was $0.2 million and was included in general and administrative expense in the consolidated statement of operations. There were no impairment charges during the first three months ended March 31, 2018. The impairment charges are a result of circumstances that indicated that the carrying values of the assets were not fully recoverable. The Company utilizes the discounted cash flow method to determine the fair value of the capitalized software assets.

The following table sets forth long-lived tangible assets by geographic area (in thousands):

	March 31, 2019		December 31, 2018
Long-lived tangible assets:
United States	$	17,214	$	18,217
International		474		490
Total long-lived tangible assets	$	17,688	$	18,707