8.    Income Taxes

The Company recorded a provision for income taxes of $7,000 for the nine months ended September 30, 2019 and $8,000 for the nine months ended September 30, 2018. The provision for income taxes recorded for the nine months ended 2019 and 2018 was primarily due to state income tax expense.

The Company’s effective tax rate was (0.09)% for the nine months ended September 30, 2019 and (0.01)% for the nine months ended September 30, 2018. The difference between the effective tax rate and the federal statutory tax rate for the nine months ended September 30, 2019 and 2018 primarily relates to the valuation allowance on the Company’s deferred tax assets.

For interim periods, the Company estimates its annual effective income tax rate and applies the estimated rate to the year-to-date income or loss before income taxes. The Company also computes the tax provision or benefit related to items reported separately and recognizes the items net of their related tax effect in the interim periods in which they occur. The Company also recognizes the effect of changes in enacted tax laws or rates in the interim periods in which the changes occur.

As of September 30, 2019, the Company retains a full valuation allowance on its deferred tax assets. The realization of the Company’s deferred tax assets depends primarily on its ability to generate taxable income in future periods. The amount of deferred tax assets considered realizable in future periods may change as management continues to reassess the underlying factors it uses in estimating future taxable income.

The provision for income taxes for the nine months ended September 30, 2019 and 2018 was calculated on a jurisdiction basis.