On December 22, 2017, the 2017 Tax Cut and Jobs Act (“the Act”) was enacted into law and the new legislation contains several key tax provisions, including a one-time mandatory transition tax on undistributed foreign earnings and a reduction of the corporate income tax rate to 21% effective January 1, 2018, among others. The Company is required to recognize the effect of the tax law changes in the period of enactment, such as determining the estimated transition tax, re-measuring its U.S. deferred tax assets and liabilities at a 21% rate as well as reassessing the net realizability of its deferred tax assets and liabilities. The one-time transition tax does not apply to the Company as it does not have any undistributed foreign earnings. The provisional amount related to the re-measurement of its deferred tax balance is a reduction of approximately $9.9 million. Due to the corresponding valuation allowance fully offsetting deferred taxes, there is no income statement impact. Upon completion of our 2017 U.S. income tax return in 2018 we may identify additional re-measurement adjustments to our recorded deferred tax assets. We will continue to assess our provision for income taxes as future guidance is issued, but do not currently anticipate significant revisions will be necessary. Any such revisions will be treated in accordance with the measurement period guidance outlined in SAB 118.

The loss before provision for income taxes consisted of the following (in thousands):

The Company had no income tax expense due to operating losses incurred for the years ended December 31, 2017 and 2016. The Company accounts for income taxes in accordance with ASC 740, which 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 currently not likely to be realized and, accordingly, has provided a full valuation allowance. The valuation decreased by approximately $5.3 million during the year ended December 31, 2017 and increased by approximately $283,000 during the year ended December 31, 2016.

The Company’s deferred tax assets are as follows (in thousands):

Net operating losses and tax credit carryforwards as of December 31, 2017, are as follows (in thousands):

The effective tax rate of the Company’s provision (benefit) for income taxes differs from the federal statutory rate as follows:

Utilization of U.S. net operating losses and tax credit carryforwards may be limited by “ownership change” rules, as defined in Section 382 of the Internal Revenue Code. Similar rules may apply under state tax laws. The Company has not conducted a study to-date to assess whether a limitation would apply under Section 382 of the Internal Revenue Code as and when it starts utilizing its net operating losses and tax credits. The Company will continue to monitor activities in the future. In the event the Company previously experienced an ownership change, or should experience an ownership change in the future, the amount of net operating losses and research and development credit carryovers available in any taxable year could be limited and may expire unutilized.

The Company establishes reserves for uncertain tax positions based on the largest amount that is more-likely-than-not to be sustained. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. It is the Company’s policy to recognize interest and penalties related to income tax matters in income tax expense. As of December 31, 2017 and 2016, respectively, the Company has no accrued interest or penalties related to uncertain tax positions.

The Company files income tax returns in the U.S. federal jurisdiction and various state jurisdictions. In the normal course of business, the Company is subject to examination by their respective taxing authorities. The Company is not currently under audit by the Internal Revenue Service or other similar state or local authority. The statute of limitations remain effectively open for all tax years from inception (2007) through 2017. Tax years outside the normal statute of limitations remain open to examination by tax authorities due to tax attributes generated in earlier years which have been carried forward and may be examined and adjusted in subsequent years when utilized.

The following table summarizes the activity related to the Company’s gross unrecognized tax benefits for the years ended December 31, 2017 and 2016 (in thousands):

The following table summarizes the activity in the Company’s Valuation Allowance and Qualifying Accounts for the years ended December 31, 2017 and 2016 (in thousands):