The Transportation Security Administration TSA

Before September 11, 2001, airport security was the airlines' job, done by low-wage contractors under loose federal rules. The hijackers passed through checkpoints carrying box cutters that were then permitted. Ten weeks later, on November 19, 2001, the Aviation and Transportation Security Act federalized screening and created the Transportation Security Administration in the Department of Transportation. Within a year it had hired and trained about 50,000 screeners and taken over checkpoints at every commercial airport. It moved to the new Department of Homeland Security in March 2003.

Passenger and baggage screening is the agency's core work. Transportation Security Officers check identification, scan carry-on and checked bags, and screen travelers with body scanners and metal detectors at about 430 airports, handling around 2.5 million people on an average day and more than 3 million on the busiest. TSA PreCheck, which allows vetted travelers through faster lanes, now covers tens of millions of members. The agency also runs the Federal Air Marshal Service, vets passengers against terrorist watch lists through the Secure Flight program, and sets security rules for rail, transit, pipelines, and ports, though its role outside aviation is much smaller.

About 60,000 people work for TSA, most of them screeners. Its Administrator is appointed for a five-year term and confirmed by the Senate. Many of its rules trace to specific plots: shoe screening after the 2001 shoe bomber, liquid limits after the 2006 transatlantic plot, and body scanners after the 2009 underwear bomber. Its effectiveness is debated. Internal tests have repeatedly found screeners missing simulated weapons, while defenders note there has been no successful hijacking of a U.S. airliner since 2001.

The agency has been called security theater by critics who doubt its rules make flying safer, and indispensable by those who credit its deterrent effect. Its workforce has long had among the lowest morale and highest turnover in government. In 2025 it ended the requirement for most passengers to remove their shoes, began enforcing REAL ID, and ended the screeners' collective bargaining agreement, a move unions challenged in court. Proposals to return screening to private contractors under federal supervision, already allowed at a handful of airports, resurfaced.