Income Tax Provision

9 Months Ended

Sep. 30, 2019

Income Tax Disclosure [Abstract]

Income Tax Provision

Income Tax Provision

We had an effective income tax rate of 0.4% and 11.0% for the three and nine months ended September 30, 2019, respectively, compared to negative 0.8% and negative 0.1% for the three and nine months ended September 30, 2018, respectively. The change in the effective tax rate for the three and nine months ended September 30, 2019, as compared to the same period in 2018, was principally driven by the fluctuations of the excess tax benefits related to stock incentive awards.

The effective income tax rates for the periods presented were different from the statutory United States federal income tax rate of 21% due to excess tax benefits related to stock incentive awards, state income taxes, non-deductible business expenses, and the tax benefit of research tax credits. The excess tax benefits related to stock incentive awards realized were $11.6 million and $18.6 million for the three and nine months ended September 30, 2019, respectively, compared to $9.3 million and $30.0 million for the three and nine months ended September 30, 2018, respectively. Excluding the excess tax benefits, the effective rate was 28.9% and 27.6% for the three and nine months ended September 30, 2019, compared to 23.3% and 25.8% for the three and nine months ended September 30, 2018, respectively.

We made tax payments of $18.1 million and $6.8 million in the nine months ended September 30, 2019, and 2018, respectively.