5. Income Taxes

The difference between the U.S. federal statutory tax rate of 35% and the Company’s effective tax rates for the three months ended March 31, 2016 and 2015 was principally due to state income taxes.

The Company had unrecognized tax benefits of approximately $0.6 million as of March 31, 2016 and December 31, 2015, which were included in other liabilities in the accompanying consolidated balance sheets.

The Company’s policy is to recognize interest and penalties related to income tax liabilities as a component of income tax expense in the consolidated statements of operations. The amount of interest and penalties charged to income tax expense because of the unrecognized tax benefits was not significant for the three months ended March 31, 2016 and 2015.

The Company is subject to taxation in various jurisdictions. The Company’s tax returns for 2012 through 2014 are currently under examination by U.S. federal authorities. The company’s tax returns are subject to examination by various state authorities for the years 2011 through 2014.