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

				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

				As of December 31, 2018
	Gross carrying amount		Amortization period	Accumulated amortization			Net carrying amount
Capitalized software development costs	$	45,677	3 years	$	(32,784	)	$	12,893
Total capitalized software development costs	$	45,677		$	(32,784	)	$	12,893

The Company capitalized software development costs of $8.8 million, $8.8 million and $6.2 million during the years ended December 31, 2019, 2018 and 2017, respectively.

Amortized expense for capitalized software development costs was $7.0 million, $5.9 million and $5.0 million during the years ended December 31, 2019, 2018 and 2017, respectively. Amortization of capitalized software development costs is classified within cost of revenue in the consolidated statements of operations and comprehensive loss. During the year ended December 31, 2019, the Company retired $4.6 million of fully amortized capitalized software development costs.

The expected amortization, as of December 31, 2019, for each of the next three years is as follows (in thousands):

2020	$	7,069
2021		4,573
2022		2,645
	$	14,287