INCOME TAXES

We file income tax returns in the U.S. federal jurisdiction, as well as in various state and local jurisdictions. With few exceptions, we are no longer subject to U.S. federal, state, and local, or non-United States income tax examinations by tax authorities for years before 2012. Our practice is to recognize interest and penalties related to income tax matters in income tax expense when and if they become applicable. At December 31, 2015 and 2014, respectively, there were no accrued interest and penalties related to uncertain tax positions.

The following table shows the components of income (loss) from continuing operations before income taxes (in thousands):



	For the year ended December 31,
	2015		2014			2013

United States	$	9,620	$	(4,246	)	$	(5,907	)
Income (loss) from continuing operations before income taxes	$	9,620	$	(4,246	)	$	(5,907	)

The following table shows the components of the provision for income taxes from continuing operations (in thousands):



	For the year ended December 31,
	2015		2014		2013
Current:
U.S. federal	$	123	$	—	$	—
State	26		—		—
Provision for income taxes	$	149	$	—	$	—

The principal items accounting for the difference between income taxes computed at the U.S. statutory rate and the provision for income taxes from continuing operations reflected in our Consolidated Statements of Operations are as follows:



	For the year ended December 31,
	2015		2014		2013

U.S. statutory rate	34.0	%	34.0	%	34.0	%
State taxes (net of federal tax benefit)	0.2		1.0		0.5
Valuation allowance	(27.9	)	(19.8	)	(31.2	)
Interest amortization expense	—		(22.5	)	(2.5	)
Other	(4.8	)	7.3		(0.8	)
	1.5	%	0.0	%	0.0	%

The tax effects of temporary differences that give rise to significant portions of the deferred tax assets are as follows (in thousands):



	At December 31,
	2015			2014			2013

Allowance for doubtful accounts	$	18		$	11		$	15
Accrued expenses and other reserves	2,244			2,082			1,960
Tax credits, deferred R&D, and other	122			44			87
Net operating loss	5,384			6,871			3,989
Valuation allowance	(7,768		)	(9,008		)	(6,051		)
Net deferred tax assets	$	—		$	—		$	—

Our effective tax rate was lower than the statutory tax rate primarily due to a decrease in the valuation allowance as a result of the utilization of net operating loss carry-forwards. We utilized $6.2 million of federal our net operating loss carry-forward in 2015.

Since we believe it is more likely than not that the benefit from net operating loss carry-forwards will not be realized, we have provided a full valuation allowance against our deferred tax assets at December 31, 2015 and 2014, respectively. We had no net deferred tax liabilities at December 31, 2015 or 2014, respectively. There was no federal tax expense for 2014 or 2013, due to an increase to the valuation allowance. In 2015, we recognized Federal tax expense as a result of the alternative minimum tax.

Deferred income tax assets are reduced by a valuation allowance when it is more likely than not that some portion of the deferred income tax assets will not be realized. In considering the need for a valuation allowance, we assess all evidence, both positive and negative, available to determine whether all or some portion of the deferred tax assets will not be realized. Such evidence includes, but is not limited to, recent earnings history, projections of future income or loss, reversal patterns of existing taxable and deductible temporary differences, and tax planning strategies. We will continue to evaluate the need for a valuation allowance on a quarterly basis.

At December 31, 2015, we had net operating loss carry-forwards of approximately $69.1 million for U.S. federal, state, and local income tax purposes. However, due to changes in our capital structure, approximately $14.8 million of this amount is available to offset future taxable income after the application of the limitations found under Section 382 of the IRC. As a result of this limitation, in 2016, we only expect to have approximately $6.0 million of the net operating loss carry-forward available for use. If not utilized, these carry-forwards will begin to expire in 2021 for federal purposes and in 2021 or sooner for state and local purposes. Additionally, the changes to our capital structure have subjected, and will continue to subject our net operating loss carry-forward to an annual limitation as discussed further below. This limitation will significantly restrict our ability to utilize the carry-forward to offset taxable income in future periods.

The IRC imposes restrictions on the utilization of various carry-forward tax attributes in the event of a change in ownership, as defined by IRC Section 382. During 2015, we completed an IRC Section 382 review and the results of this review indicate ownership changes have occurred which would cause a limitation on the utilization of carry-forward attributes. Our gross capital loss carry-forwards, net operating loss carry-forwards, and research and development credits are all subject to limitation. Under these tax provisions, the limitation is applied first to any capital losses, next to any net operating losses, and then to any general business credits. The Section 382 limitation is currently estimated to result in the expiration of $54.3 million of net operating loss carry-forwards and $299 thousand of research and development credits. A valuation allowance has been established to reserve for the potential benefits of the capital loss carry-forwards and the remaining net operating loss carry-forwards in the consolidated financial statements to reflect the uncertainty of future taxable income required to utilize available tax loss carry-forwards.