4. Income Taxes

The Company’s provision for income taxes for the three months ended March 31, 2020 is based on the actual effective tax rate for the year to date while that for the three months ended March 31, 2019 is based on the estimated annual effective tax rate for the year, plus discrete items. The following table presents the provision for income taxes and the effective tax rates for the three months ended March 31, 2020 and 2019 (in thousands):


	Three Months Ended
	March 31,
	2020			2019
Income (loss) before income tax provision (benefit)	$	(11,089)		$	6,920
Income tax provision (benefit)		(1,857)			1,901
Effective tax rate		16.7	%		27.5	%

The difference between the Company’s effective tax rate for the three months ended March 31, 2020 and 2019 and the US statutory rate of 21% primarily relates to nondeductible expenses, federal income tax credits, state income taxes (net of federal benefit), and a net increase in valuation allowances.

On March 27, 2020, the U.S. federal government enacted the Coronavirus Aid, Relief, and Economic Act (the “CARES Act”). The CARES Act is an emergency economic stimulus package in response to the coronavirus outbreak which, among other things, contains numerous income tax provisions. While the Company continues to evaluate the impact of the CARES Act, it does not currently believe it will have a material impact on the Company’s consolidated financial statements or related disclosures.