In 2015, TSA screened or oversaw the screening of more than 708 million passengers at more than 450 U.S airports. In carrying out the screening process, TSA is responsible for ensuring the security of civil aviation while also managing the efficient flow of passengers. TSA employs screening personnel, called TSOs, to carry out passenger and baggage screening operations. Each year, TSA tests TSO performance as part of its efforts to monitor the effectiveness of aviation security screening. In 2011, TSA began providing expedited screening procedures to selected passengers, intended to strengthen security and improve the passenger experience by shortening lines and wait times. This testimony addresses the extent to which TSA (1) has taken steps to improve the security effectiveness of expedited screening and (2) uses TSO performance testing data to enhance TSO performance in screening for prohibited items. This statement is based on reports GAO issued in May 2016 and December 2014, and selected updates. Among other things, GAO analyzed TSA documentation on expedited screening and TSO testing data.