INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2019

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,
	2019			2018			2017
	(in thousands)
Domestic	$	(489,747	)	$	(309,294	)	$	(45,686	)
Foreign		(224,133	)		(53,316	)		(2,942	)
Total	$	(713,880	)	$	(362,610	)	$	(48,628	)

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,
	2019			2018			2017
	(in thousands)
Current provision:
Federal	$	—		$	(110	)	$	204
State		521			(653	)		1,856
Foreign		1,050			311			—
Total current provision		1,571			(452	)		2,060
Deferred benefit:
Federal		(15	)		—			—
State		(5	)		—			—
Foreign		(356	)		(240	)		—
Total deferred benefit		(376	)		(240	)		—
Total current provision	$	1,195		$	(692	)	$	2,060

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,
	2019				2018				2017
Federal income tax rate		21.0		%		21.0		%		34.0		%
State taxes		6.3				12.3				(27.7	)
Research and development and other tax    credits		3.3				3.1				8.5
Valuation allowance		(16.8	)			(45.5	)			(93.2	)
Permanent differences		1.8				6.9				6.4
Sarepta International C.V. return to provision		—				(0.1	)			62.1
Impact of tax reform, net of valuation    allowance		—				—				5.9
Basis difference in subsidiary		(8.4	)			—				—
Foreign rate differential		(7.4	)			(0.9	)			(0.6	)
Other		—				3.4				0.4
Effective tax rate		(0.2	)	%		0.2		%		(4.2	)	%

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,
	2019			2018
	(in thousands)
Deferred tax assets:
Net operating loss carryforwards	$	304,033		$	212,342
Difference in depreciation and amortization		40,095			55,162
Research and development tax credits		103,806			67,309
Stock-based compensation		24,114			15,538
Lease liabilities		15,796			4,831
Deferred revenue		939			888
Capitalized inventory		18,255			22,943
Other		16,270			15,727
Total deferred tax assets		523,308			394,740
Deferred tax liabilities:
Right of use asset		(10,782	)		—
Debt discount		(23,099	)		(25,162	)
Total deferred tax liabilities		(33,881	)		(25,162	)
Valuation allowance		(488,829	)		(369,345	)
Net deferred tax assets	$	598		$	233

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,
	2019			2018		2017
	(in thousands)
Balance at beginning of the period	$	37,544		$	5,134	$	4,644
Increase related to current year tax positions		4,275			2,164		735
Increase related to prior year tax positions		109			30,246		—
Decrease related to prior year tax positions		(175	)		—		(245	)
Balance at end of the period	$	41,753		$	37,544	$	5,134