The geographical distribution of loss before income taxes are summarized below (in thousands).

	December 31,
	2019			2018
United States	$	(30,729	)	$	(11,830	)
Foreign		(45	)		(11	)
Loss before income taxes	$	(30,774	)	$	(11,841	)
Loss resulting from discontinued operations	$	—		$	(1,494	)
Taxes allocated to discontinued operations	$	—		$	—

The provision for income tax benefit differs from the amount estimated by applying the statutory federal income tax rate to the operating loss from continuing operations due to the following (in thousands).

	December 31,
	2019			2018
Tax on the loss before income tax expense computed at the federal statutory rate	$	(6,463	)	$	(2,486	)
State tax (benefit) at statutory rate, net of federal benefit		(1,691	)		(187	)
Foreign rate differential		10			2
Change in valuation allowance		6,696			4,143
Change in research and development credits		(200	)		(99	)
Stock based compensation—ISOs		149			143
Change in fair value of warrants		1,461			(110	)
Change in fair value of contingent consideration		61			119
Gain on deconsolidation		—			(4	)
Disallowance of loss on discontinued operations		—			(426	)
Change in net operating loss true up		(725	)		(590	)
Change in state rate true up		701			—
Change in temporary difference true up		—			(456	)
Other		1			(49	)
Provision for income tax benefit	$	—		$	—

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities are as follows at December 31, 2019 and 2018 (in thousands).

	December 31,
	2019			2018
Non-current deferred tax assets:
Federal and state net operating loss carryforwards	$	35,091		$	28,532
Research and other credits		2,349			2,037
Reserves and accruals		77			52
Assets held for sale		—			15
Fixed assets		71			67
Capital loss carryover		1,115			425
Stock based compensation		85			70
Lease liability		131			—
Other deferred tax assets		196			542
Gross non-current deferred tax assets		39,115			31,740
Intangible assets		(4,623	)		(4,062	)
Right-of-use assets		(118	)		—
Total non-current deferred tax liabilities		(4,741	)		(4,062	)
Total deferred tax assets		34,374			27,678
Valuation allowance		(34,374	)		(27,678	)
Net deferred tax assets	$	—		$	—

The Company has recorded a full valuation allowance against its net deferred tax assets due to the uncertainty as to whether such assets will be realized. The valuation allowance increased by $6.7 million from December 31, 2018 to December 31, 2019 primarily due to the generation of current year net operating losses, capital losses and research and development credits claimed.

As of December 31, 2019, the Company had $150.5 million of federal, $82.5 million of state and approximately $299,000 of foreign net operating losses available to offset future taxable income. The federal net operating loss carryforwards begin to expire in 2020, the federal net operating loss carryforwards of $31.7 million may be carried forward indefinitely, the state net operating loss carryforwards will begin to expire in 2028 and the foreign net operating loss carryforward can be carried forward indefinitely, if not utilized. The Company adjusted its state net operating loss carryforward by $10.4 million for the year ended December 31, 2018. As of December 31, 2019, the Company also had $1.4 million of federal and approximately $916,000 of state research and development credit carryforwards. The federal research and development credit carryforward begin to expire in 2024 and the state research and development credit can be carried forward indefinitely.

Utilization of the net operating loss and tax credit carry forwards are subject to an annual limitation due to the ownership percentage change limitations provided by the Internal Revenue Code of 1986 and similar state provisions. The annual limitation may result in the expiration of the net operating loss before utilization. The Company completed Section 382 analysis through December 2016 and determined that an ownership change, as defined under Section 382 of the Internal Revenue Code, occurred in June 2016. The Company’s tax attributes are subject to an annual limitation of $0.5 million per year for federal purposes. For years ended after December 31, 2016, the utilization of net operating losses and tax credit carryforwards are subject to further limitation in the event an additional ownership change were to occur for tax purposes. The Company has not completed an updated analysis of whether there was an ownership change, as defined under Section 382 of the Internal Revenue Code, resulting from the issuance of new shares during 2018 through 2019 and, as such, is not able at this time to determine the impact on the net operating loss (“NOL”) carryforwards, if any, as of the date of these consolidated financial statements.

United States taxes and foreign withholding taxes have not been provided on undistributed earnings for certain non-United States subsidiaries as of December 31, 2019, as the earnings, if any, are intended to be indefinitely reinvested.

The following tables summarize the activities of gross unrecognized tax benefits (in thousands).

	December 31,
	2019			2018
Beginning balance	$	964		$	854
Increase related to prior year tax positions		7			23
Decrease related to prior year tax positions		(4	)		—
Increase related to current year tax positions		144			87
Ending balance	$	1,111		$	964

The Company uses the “more likely than not” criterion for recognizing the tax benefit of uncertain tax positions and to establish measurement criteria for income tax benefits. The Company has determined it has $1.1 million of unrecognized assets and liabilities related to uncertain tax positions as of December 31, 2019. Changes in the unrecognized tax benefits within the next 12 months are expected to be similar to prior years and should not significantly increase or decrease. In the event the Company should need to recognize interest and penalties related to unrecognized tax liabilities, this amount will be recorded as a component of other expense.

There were no unrecognized tax benefits that would impact the effective tax rate as of December 31, 2019 and December 31, 2018. As of December 31, 2019, unrecognized tax benefits of $1.1 million would be offset by a change in valuation allowance.

The Company files income tax returns in the U.S. federal jurisdiction, certain state jurisdictions and United Kingdom. In the normal course of business, the Company is subject to examination by federal, state, local and foreign jurisdictions, where applicable. In the U.S federal jurisdiction, tax years 1999 forward remain open to examination, in the state tax jurisdiction, years 2008 forward remain open to examination and in the foreign jurisdiction, years 2015 forward remain open to examination. The Company is currently not under audit by any federal, state, local or foreign jurisdiction.

The Jobs Act also establishes global intangible low-taxed income, or “GILTI,” provisions that impose a tax on foreign income in excess of a deemed return on intangible assets of foreign corporations. The Company’s accounting policy for the income tax effects of GILTI will be to recognize those taxes as expenses in the period incurred. In 2019, the Company’s foreign subsidiary realized a tested loss for the period and therefore, the Company did not have a GILTI inclusion for the year.