"Dozens of temporary tax provisions expired at the end of 2013, and several other temporary tax provisions are scheduled to expire at the end of 2014. Most of the provisions that expired at the end of 2013 have been part of past temporary tax extension legislation. Most recently, many temporary tax provisions were extended as part of the American Taxpayer Relief Act (ATRA; P.L. 112-240). Collectively, temporary tax provisions that are regularly extended by Congress--often for one to two years--rather than being allowed to expire as scheduled are often referred to as 'tax extenders.' On April 3, 2014, the Senate Finance Committee voted to report the Expiring Provisions Improvement Reform and Efficiency (EXPIRE) Act. The EXPIRE Act would extend most expired and soon-to-expire provisions through 2015. An earlier proposal, S. 1859, introduced by Senator Reid on December 19, 2013, would provide a one-year extension for provisions that expired in 2013. House Ways and Means Committee Chairman Dave Camp has indicated that extenders will be addressed in the Ways and Means Committee during 2014. Chairman Camp has emphasized that extenders should be evaluated to see which provisions should be made permanent."
CRS Report for Congress, R43124