A reconciliation of the differences between the United States statutory federal income tax rate and the effective tax rate as provided in the statement of operations is as follows:

	Year ended December 31,
	2018			2017
Tax computed at the federal statutory rate		21.0	%		34.0	%
State income taxes, net of federal benefits		2.7			5.8
Tax reform—tax rate change		—			(18.6	)
Nondeductible expenses		(2.0	)		—
Other		(2.2	)		—
Change in valuation allowance		(19.5	)		(21.2	)
		—			—

The federal and state income tax provision is summarized as follows (in thousands):

	Year ended December 31,
	2018		2017
Current
Federal	$	—	$	—
State		10		1
		10		1
Deferred
Federal		—		—
State		—		—
		—		—
Income tax expense	$	10	$	1

Deferred income taxes reflect the net tax effects of (a) temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for tax purposes, and (b) operating losses and tax credit carryforwards.

The tax effects of significant components of the Company’s deferred tax assets (liabilities) are as follows (in thousands):

	December 31,
	2018			2017
Deferred Tax Assets:
Net operating loss carryforwards	$	6,990		$	1,994
Other accruals		88			79
Reserves		203			142
Deferred revenue		661			697
Intangible assets		353			618
Stock-based compensation		6,464			4,314
	$	14,759		$	7,844
Deferred Tax Liabilities:
Property and equipment		(888	)		(5	)
Valuation allowance	$	(13,871	)	$	(7,839	)
Total deferred taxes	$	—		$	—

At December 31, 2018, the Company had available federal and state net operating loss carryforwards of approximately $27.7 million and $23.6 million, respectively, which may be used to offset future federal and state taxable earnings. The federal and state net operating losses begin expiring in 2029. Use of these net operating loss carryforwards may be significantly limited under the tax rules regarding the use of losses following an ownership change under Internal Revenue Code (“IRC”) Section 382. The Company has not completed an IRC Section 382 analysis regarding the limitation of net operating losses.

As of December 31, 2018, the Company does not have any unrecognized tax benefits. The Company does not anticipate that the amount of unrecognized tax benefits will significantly increase or decrease in the next 12 months. There were no interest and penalties accrued as of December 31, 2018. The Company files U.S. federal and various states income tax returns, which are subject to examination by the taxing authorities for years 2015 and later.

ASC 740, Income Taxes, requires that the tax benefit of net operating losses, temporary differences and credit carryforwards be recorded as an asset to the extent that management assesses that realization is “more likely than not.” Realization of the future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Because of the Company’s recent history of operating losses, management believes that recognition of the deferred tax assets arising from the above-mentioned future tax benefits is not currently more likely than not to be realized and, accordingly, has provided a full valuation allowance at December 31, 2018 and 2017.

The difference between the statutory federal income tax rate and the effective income tax rate reported in the statements of operations is primarily due to the Tax Act (as defined below), state income taxes and the change in the valuation allowance.

The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. The Company is no longer subject to audit by U.S. federal, state and local tax authorities for years before 2014. The Company is not currently under examination by any taxing jurisdiction. As of December 31, 2018 and 2017, there is no accrued interest or penalties recorded in the financial statements. However, the net operating loss carryover may be adjusted three years from the date the loss is utilized on an income tax return.

On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act (the “Tax Act”). The Tax Act significantly changes U.S. tax law by, among other things, lowering corporate income tax rates, eliminating certain deductions, allowing full expensing of capital spending, implementing a territorial tax system, and imposing a repatriation tax on deemed repatriated earnings of foreign subsidiaries. The Company has completed its analysis of the Tax Act. The Tax Act permanently reduces the U.S. corporate income tax rate from a maximum of 34% to a flat 21% rate, effective January 1, 2018. As a result of the reduction in the U.S. corporate income tax rate from 34% to 21% under the Tax Act, the Company revalued its ending net deferred tax assets at December 31, 2017. The impact of this revaluation was offset by a reduction in the valuation allowance, thus having no impact on the income tax expense recognized in the statement of operations for the year ended December 31, 2017.