Income Taxes

3 Months Ended

Mar. 31, 2020

Income Taxes [Abstract]

Income Taxes

5.  Income Taxes

The Coronavirus Aid, Relief, and Economic Security, or CARES, Act was enacted in March 2020. We considered our ability to estimate annual effective tax rates based on our pre-tax income projections, the income tax effects of the CARES Act, the realizability of our net deferred tax assets and the appropriateness of our valuation allowances.

Under the Tax Cut and Jobs Act of 2017, the utilization of federal net operating losses was limited to 80 percent of taxable income. The CARES Act temporarily removed this limitation and provides for the utilization of net operating loss carryforwards to offset 100 percent of taxable income. The 80 percent limitation enacted by the Tax Act is reinstated for tax years beginning in 2021.

We recorded an income tax benefit of $3.3 million for the three months ended March 31, 2020, compared to income tax expense of $31.0 million for the same period in 2019. We recorded an income tax benefit for the three months ended March 31, 2020 primarily due to Ionis’ pre-tax loss for the period and the $1.7 million tax benefit related to Akcea. We did not record a tax benefit as a result of Akcea’s pre-tax loss in the first quarter of 2020 because Akcea maintains a full valuation allowance against its deferred tax assets.

Our effective tax rate may vary from the U.S. federal statutory rate due to the change in the mix of earnings in tax jurisdictions with different statutory rates, benefits related to tax credits, the tax impact of non-deductible expenses and other permanent differences between income before taxes and taxable income, and changes to tax laws or rates. Our effective income tax rate of 5.28 percent for the three months ended March 31, 2020 differed from the U.S. federal statutory rate of 21 percent primarily due to Ionis’ pre-tax loss for the period and the $1.7 million tax benefit related to Akcea.