The TSA says Southwest Airlines became the 8th U.S. airline to participate in the TSA PreCheck program for expedited security screening.

Southwest will invite certain members of its Rapid Rewards frequent flyer program who are U.S. citizens to participate in PreCheck, which means an indicator would be embedded in their boarding pass barcodes showing that they can skip the regular security lanes and instead pass through the PreCheck lane.

Southwest CFO Tammy Romo said at a conference last week that the airline would be joining PreCheck “very soon.”

TSA PreCheck is currently available at 100 U.S. airports; the other participating airlines are Alaska, American, Delta, Hawaiian, United, US Airways and Virgin America.

JetBlue is a notable absentee.

PreCheck enables enrollees to pass through security wearing shoes, light jackets and belts; they don’t have to break out their laptops or 3-1-1 liquid gels.

The TSA says that later this year it will launch an application program that would enable more U.S. citizens and permanent residents to join PreCheck.

Photo Credit: In this Feb. 9, 2012 photo, a Southwest Airlines Boeing 737 waits to take off at Chicago's Midway Airport as another lands. AP Photo / Charles Rex Arbogast