11. Income Taxes

The components of the provision for income taxes are as follows:

	2016			2015
Current tax provision:
Federal		$	—		$	—
State			10			6
Deferred tax provision:
Federal			—			—
State			—			—
Total		$	10		$	6

A summary of the differences between the Company’s effective income tax rate and the Federal statutory income tax rate for the years ended December 31, 2016 and 2015 is as follows:

	2016		2015
Federal statutory rate		34.00%		34.00%
State income tax rate, net of federal benefit		(0.2)%		(0.05)%
Change in valuation allowance		(26.85)%		(33.95)%
Other		(7.26)%		(0.07)%
Effective income tax rate		(0.31)%		(0.07)%

Deferred tax assets are comprised of the following at December 31:

	2016			2015
Deferred tax assets:
Net operating loss carryforwards		$	5,730		$	4,732
Deferred Revenue			194			453
Depreciation and amortization			30			18
Stock-based compensation			1,089			1,105
Accrual and reserves			117			132
Research and Development Credits			96			130
Total gross deferred tax assets			7,256			6,570
Less valuation allowance			(7,256)			(6,570)
Net deferred tax assets		$	—		$	—

As of December 31, 2016, the Company has net operating loss carryforwards of approximately $16,013 for Federal and approximately $6,861 for California, which begin to expire in 2032. The Company also has Federal research and development credit carryforwards of approximately $98 at December 31, 2016 which will begin to expire in 2032.

ASC 740-10, Income Taxes, prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return and also provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition.

The Company’s ability to use operating loss carryforwards and tax credits to offset future taxable income is subject to restrictions under Section 382 of the United States Internal Revenue Code (the “Internal Revenue Code”). These restrictions may limit the future use of future operating loss carryforwards and tax credits if certain ownership changes described in the Internal Revenue Code occur. Future changes in stock ownership may occur that would create further limitations on the Company’s use of it operating loss carryforwards and tax credits. In such a situation, the Company may be required to pay income taxes, even though significant operating loss carryforwards and tax credits might exist.

As of December 31, 2016, and 2015, the Company had no unrecognized tax benefits and no adjustments to liabilities or operations were required for uncertain tax positions under ASC 740-10. The Company’s practice is to recognize interest and penalty expenses related to uncertain tax positions in income tax expense, which was zero for the years ended December 31, 2016 and 2015. The Company files income tax returns in the U.S. federal and several state tax jurisdictions.

The Company’s tax years beginning in 2012 remain open for examination by the state tax authorities for four years. The Company’s tax years beginning in 2013 remain open for examination by the federal tax authorities for three years. Tax years beginning in 2012 will remain open for examination from the date of utilization of any net operating loss or credits. The Company does not have any tax positions for which it is reasonably possible the total amount of gross unrecognized tax benefits will increase or decrease within 12 months of the year-ended December 31, 2016.