Entity information:
INCOME TAXES
 
The domestic and foreign components of loss before provision for income taxes consisted of the following (in thousands):
 
Years Ended December 31,
 
2016
 
2015
 
2014
United States
$
(67,631
)
 
$
(22,120
)
 
$
(8,732
)
Foreign
1,644

 
1,417

 
1,446

Total
$
(65,987
)
 
$
(20,703
)
 
$
(7,286
)

 
The provision for income taxes for the years presented is as follows (in thousands):
 
Years Ended December 31,
 
2016
 
2015
 
2014
Current:
 
 
 
 
 
Federal
$

 
$

 
$

State
36

 
44

 
85

Foreign
785

 
693

 
716

 
821

 
737

 
801

Deferred:

 
 
 
 
Federal
594

 
652

 

State
59

 
41

 

Foreign
1

 
(51
)
 
(35
)
 
654

 
642

 
(35
)
Provision for income taxes
$
1,475

 
$
1,379

 
$
766


 
A reconciliation of the provision for income taxes and the amount computed by applying the statutory federal income tax rate of 34% to loss before income taxes for the years presented is as follows (in thousands):
 
Years Ended December 31,
 
2016
 
2015
 
2014
Income tax benefit at statutory federal rate
$
(22,435
)
 
$
(7,039
)
 
$
(2,477
)
State taxes, net of federal benefit
63

 
56

 
(4,576
)
Change in valuation allowance
21,370

 
7,812

 
16,646

Foreign tax rate and tax law differential
27

 
(29
)
 
(43
)
Tax credits
(1,179
)
 
(1,553
)
 
(5,619
)
Stock-based compensation
1,775

 
1,932

 
957

Other permanent items
776

 
61

 
231

Other nondeductible/nontaxable items
920

 
(72
)
 
(4,586
)
Uncertain tax positions
158

 
211

 
233

Provision for income taxes
$
1,475

 
$
1,379

 
$
766


A summary of significant components of the Company’s deferred tax assets and liabilities as of December 31, 2016 and 2015 is as follows (in thousands):
 
 
December 31,
 
2016
 
2015
Deferred tax assets:
 
 
 
Allowances and reserves
$
16,032

 
$
14,639

Net operating loss and tax credit carryforwards
67,875

 
46,812

Stock-based compensation
3,033

 
3,055

Deferred revenue
8,289

 
5,966

Fixed assets and intangibles
7,661

 
6,830

Other
2,857

 
3,327

Subtotal
105,747

 
80,629

Less valuation allowance
(104,554
)
 
(80,529
)
Total deferred tax assets, net of valuation allowance
1,193

 
100

Deferred tax liabilities:


 


Goodwill
(1,346
)
 
(693
)
Unremitted foreign earnings
(748
)
 

Total deferred tax liabilities
(2,094
)
 
(693
)
Net deferred tax asset/(liability)
$
(901
)
 
$
(593
)

 
Accounting for income taxes requires that companies assess whether valuation allowances should be established against their deferred tax assets based on consideration of all available evidence, both positive and negative, using a “more likely than not” standard. This assessment considers, among other matters, the nature, frequency and amount of recent losses, the duration of statutory carryforward periods, and tax planning strategies. In making such judgments, significant weight is given to evidence that can be objectively verified. Due to the history of losses the Company has generated in the United States since inception, the Company believes that it is more-likely-than-not that all of its U.S. and state deferred tax assets will not be realized as of December 31, 2016. Therefore, the Company has recorded a full valuation allowance on its U.S. and state deferred tax assets at December 31, 2016. Should the Company determine that it would be able to realize its deferred tax assets in the foreseeable future, an adjustment to the deferred tax assets may cause a material increase to income in the period such determination is made. Significant management judgment is required in determining the period in which the reversal of a valuation allowance should occur.
 
During 2016, the Company re-evaluated its overall business strategy and determined that it no longer intends to permanently reinvest the earnings of the foreign subsidiaries abroad. The Company recorded a deferred tax liability related to the U.S. federal and state income taxes and foreign withholding taxes of $0.7 million related to remaining unremitted foreign earnings.
 
The Company has net operating loss carryforwards for federal and California income tax purposes of approximately $130.9 million and $70.9 million, respectively, as of December 31, 2016. The federal and state net operating loss carryforwards, if not utilized, will expire beginning in 2028. Utilization of the net operating loss carryforwards may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended (the “Code”), and similar state provisions. The annual limitation may result in the expiration of net operating losses before utilization. The Company has completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company became a loss corporation under the Code. However, the Company does not anticipate these limitations will significantly impact its ability to utilize the net operating losses and tax credit carryforwards.
 
The Company has approximately $10.9 million of federal research credit and $11.3 million of state research credit carryforwards. The federal credits begin to expire in 2026 and the state credits can be carried forward indefinitely.
 
As a result of certain realization requirements under income tax accounting for stock-based compensation, the table of deferred tax assets and liabilities shown above does not include certain deferred tax assets as of December 31, 2016 and 2015 that arose directly from tax deductions related to equity compensation greater than compensation recognized for financial reporting. Equity will be increased by $2.3 million if and when such deferred tax assets are ultimately realized.
 
The accounting for uncertain tax positions 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. The Company is required to recognize in the financial statements the impact of a tax position, if that position is more-likely-than-not of being sustained on audit, based on the technical merits of the position. The Company recorded a net charge for unrecognized tax benefits in 2016 of $0.5 million.
 
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 over the next year. The unrecognized tax benefits may increase or change during the next year for items that arise in the ordinary course of business. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense.
 
A tabular reconciliation of the total amounts of unrecognized tax benefits for the years presented is as follows (in thousands):
 
Year Ended December 31,
 
2016
 
2015
 
2014
Unrecognized tax benefits—at beginning of year
$
5,482

 
$
4,426

 
$
376

Increases in balances related to tax positions taken in prior years

 
14

 
1,895

Increases in balances related to tax positions taken in current year
571

 
1,053

 
2,155

Lapses in statutes of limitations
(37
)
 
(11
)
 

Unrecognized tax benefits—at end of year
$
6,016

 
$
5,482

 
$
4,426


 
The Company’s tax returns continue to remain subject to examination by U.S. federal authorities for the years 2006 through 2016 and by California state authorities for the years 2006 through 2016 due to the use of net operating losses generated in tax years prior to the statutory three-year limit.