Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income (loss) before income taxes was derived from the following jurisdictions:

The income tax expense (benefit) for the years ended December 31, 2020, 2019 and 2018 was comprised of:

Effective tax rates differ from statutory income tax rates in the years ended December 31, 2020, 2019 and 2018 as follows:

	2020			2019			2018
Statutory income tax rate		21.0	%		21.0	%		21.0	%
State income taxes		7.1			14.4			3.8
Effect of foreign operations		0.2			(1.0	)		0.2
Changes in valuation allowance		(516.5	)		(59.9	)		(20.8	)
Change in unused net operating loss and credit carryforwards		—			24.7			3.9
Change in uncertain tax positions		21.4			—			—
Research and development credit		(6.0	)		—			—
Stock-based compensation		3.7			22.3			0.2
162(m) limitation		1.9			(18.2	)		(2.9	)
Nondeductible items		1.6			(1.8	)		(3.2	)
Impact of Tax Cuts and Jobs Act		—			(1.5	)		(2.2	)
Other		(0.9	)		—			—
Effective income tax rate		(466.5	)%		0.0	%		0.0	%

Deferred tax assets (liabilities) as of December 31, 2020 and 2019 consist of the following:

	2020			2019
Gross deferred tax assets:
Net operating loss carryforward – U.S.	$	36,071		$	41,780
Net operating loss carryforward – Switzerland		106			52
Research and development tax credit carryforward		5,418			7,559
Deferred revenue		219			—
Stock-based compensation		2,954			1,999
Inventory reserve		159			307
Compensation accruals		1,304			1,154
Product reserves		2,820			2,329
Operating lease liabilities		1,546			1,763
163j interest expense limitation		—			475
Amortization		607			585
Other		145			61
Total deferred tax assets		51,349			58,064
Deferred tax liabilities:
Depreciation		(1,838	)		(1,807	)
Right-of-use asset, operating leases		(1,303	)		(1,648	)
Total deferred tax liabilities		(3,141	)		(3,455	)
Net deferred tax asset before valuation allowance		48,208			54,609
Less valuation allowance		(1,226	)		(54,609	)
Net deferred tax asset	$	46,982		$	—