INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Summary of Loss before Provision for Income Taxes by Jurisdiction

The following table summarizes the loss before the provision for income taxes by jurisdiction for the periods indicated:

	For the Year Ended December 31,
	2020			2019			2018
	(in thousands)
Domestic	$	(204,956	)	$	(489,747	)	$	(309,294	)
Foreign		(348,109	)		(224,133	)		(53,316	)
Total	$	(553,065	)	$	(713,880	)	$	(362,610	)

Summary of Provision for Income Taxes

The following table summarizes provision for income taxes in the accompanying consolidated financial statements for the periods indicated:

	For the Year Ended December 31,
	2020			2019			2018
	(in thousands)
Current provision:
Federal	$	4		$	—		$	(110	)
State		624			521			(653	)
Foreign		680			1,050			311
Total current provision		1,308			1,571			(452	)
Deferred benefit:
Federal		—			(15	)		—
State		—			(5	)		—
Foreign		(245	)		(356	)		(240	)
Total deferred benefit		(245	)		(376	)		(240	)
Total current provision	$	1,063		$	1,195		$	(692	)

Reconciliation Between Effective Tax Rate and Federal Income Tax Rate

The following table summarizes the reconciliation between the Company’s effective tax rate and the income tax rate for each of the periods indicated:

	For the Year Ended December 31,
	2020				2019				2018
Federal income tax rate		21.0		%		21.0		%		21.0		%
State taxes		4.0				6.3				12.3
Research and development and other tax    credits		6.6				3.3				3.1
Valuation allowance		(21.3	)			(16.8	)			(45.5	)
Permanent differences		2.2				1.8				6.9
Sarepta International C.V. return to provision		—				—				(0.1	)
Basis difference in subsidiary		—				(8.4	)			—
Foreign rate differential		(12.9	)			(7.4	)			(0.9	)
Other		0.2				—				3.4
Effective tax rate		(0.2	)	%		(0.2	)	%		0.2		%

Analysis of Deferred Tax Assets and Liabilities

The following table summarizes the analysis of the deferred tax assets and liabilities for each of the periods indicated: 

	As of December 31,
	2020			2019
	(in thousands)
Deferred tax assets:
Net operating loss carryforwards	$	333,703		$	304,033
Difference in depreciation and amortization		31,259			40,095
Research and development tax credits		159,917			103,806
Stock-based compensation		31,212			24,114
Lease liabilities		13,120			15,796
Deferred revenue		—			939
Capitalized inventory		35,959			18,255
Other		28,381			16,270
Total deferred tax assets		633,551			523,308
Deferred tax liabilities:
Right of use asset		(8,772	)		(10,782	)
Debt discount		(18,044	)		(23,099	)
Total deferred tax liabilities		(26,816	)		(33,881	)
Valuation allowance		(605,848	)		(488,829	)
Net deferred tax assets	$	887		$	598

Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

The follow table summarizes the reconciliation of the beginning and ending amount of total unrecognized tax benefits for each of the periods indicated:

	For the Year Ended December 31,
	2020		2019			2018
	(in thousands)
Balance at beginning of the period	$	41,753	$	37,544		$	5,134
Increase related to current year tax positions		6,722		4,275			2,164
Increase related to prior year tax positions		—		109			30,246
Decrease related to prior year tax positions		—		(175	)		—
Balance at end of the period	$	48,475	$	41,753		$	37,544