Capitalized software development costs consisted of the following (in thousands):

				As of March 31, 2020
	Gross carrying amount		Amortization period	Accumulated amortization			Net carrying amount
Capitalized software development costs	$	51,867	3 years	$	(37,473	)	$	14,394
Total capitalized software development costs	$	51,867		$	(37,473	)	$	14,394

				As of December 31, 2019
	Gross carrying amount		Amortization period	Accumulated amortization			Net carrying amount
Capitalized software development costs	$	49,909	3 years	$	(35,622	)	$	14,287
Total capitalized software development costs	$	49,909		$	(35,622	)	$	14,287

The Company capitalized software development costs of $2.0 million and $2.1 million for the three months ended March 31, 2020 and 2019, respectively.

Amortization expense for capitalized software development costs was $1.9 million and $1.5 million for the three months ended March 31, 2020 and 2019, respectively. Amortization of capitalized software development costs is classified within cost of revenue in the consolidated statements of operations.

The expected amortization of capitalized software development costs, as of March 31, 2020, for each of the following years is as follows (in thousands):


2020 (for the remaining nine months)	$	5,770
2021		5,198
2022		3,270
2023		156
	$	14,394