The Transportation Security Administration processed more than 900 million travelers through U.S. checkpoints in 2025, according to TSA data — and during peak travel windows like spring break and summer, average checkpoint wait times at major hubs regularly exceed 30 minutes. What the agency is actually scanning for, and what predictably slows everything down, is something most travelers still get wrong every year.
Understanding how TSA screening works isn't just useful trivia. It directly affects whether you make your flight, whether your laptop ends up dented on the conveyor belt, and whether the officer waving you into a secondary inspection pod is going to make you miss your connection. The rules have also evolved significantly since the pandemic, and several common assumptions about what's allowed are now outdated.
TSA's primary screening technology at most major airports is the Advanced Imaging Technology (AIT) body scanner — the millimeter-wave machine that asks you to raise your arms. These scanners don't see through clothing in the traditional X-ray sense. They detect anomalies on the body surface, flagging anything that isn't skin or a thin fabric layer. That includes forgotten chapstick in a shirt pocket, a thick belt buckle, and — critically — any item denser than air in a carry-on bag that wasn't properly removed before the X-ray belt. The algorithm flags the area, and an officer must physically resolve the alert. That's the moment most secondary checks begin.
The 3-1-1 liquids rule — containers of 3.4 ounces or less, in one quart-sized clear bag, one bag per traveler — remains the single most violated carry-on rule at U.S. checkpoints. TSA confiscated more than 10 million prohibited items in 2024, with oversized liquids representing the largest single category. The agency's enforcement has tightened since 2023, when TSA updated its prohibited items database and increased officer training on gel-based items, which had historically been inconsistently screened. Gel shoe inserts, protein shakes, and even peanut butter now consistently trigger alerts if they exceed 3.4 ounces and are found in carry-ons.
Electronics remain the other major checkpoint bottleneck. The rule requiring laptops and large electronics to be removed from bags and placed in a separate bin still applies to standard screening lanes. A device larger than a standard cell phone — including tablets, e-readers, and portable gaming consoles — must come out. Travelers who forget this and repack mid-lane create the cascading delays that build 20-minute waits out of what should take three minutes per person.
What TSA isn't primarily looking for — despite common traveler anxiety — is cash. Carrying large amounts of cash is not illegal, and TSA officers are not customs agents. Their mandate is aviation security, specifically explosives, weapons, and incendiary devices. They are, however, required to report currency amounts over $10,000 to law enforcement, as part of a coordination protocol with CBP and DEA. If you're pulled aside with a large amount of cash, TSA may flag the issue, but a seizure would require a separate law enforcement action.
Travelers who reliably move through checkpoints faster share a few common behaviors. They wear slip-on shoes or shoes without metal hardware. They carry electronics in the outermost compartment of their bag, not buried at the bottom. They use a dedicated quart-sized toiletry bag that lives permanently near the top of their carry-on. And increasingly, they carry a metal-free water bottle — since TSA allows empty containers through, which avoids the liquid rule entirely and saves money on overpriced terminal drinks.
**What this means for you**
Spring break 2026 is running from late March through mid-April, and TSA has deployed additional staffing at the 25 busiest U.S. airports for the period, according to an agency press release. Wait times at Atlanta's Hartsfield-Jackson, LAX, and Chicago O'Hare are projected to peak between 7 a.m. and 10 a.m. on Friday and Sunday mornings during the break window. TSA recommends arriving two hours before domestic flights and three hours before international departures.
The practical implication for budget travelers is real: missing a flight due to a checkpoint delay rarely results in a free rebooking under the terms of basic economy tickets. Airlines including Spirit, Frontier, and American's basic economy tier explicitly categorize "security delays" as passenger-side issues, meaning travelers bear the rebooking cost. The $100-$200 price of a TSA PreCheck enrollment — which bypasses the standard screening lane entirely — frequently pays for itself after one avoided rebooking.
The checkpoint system is also changing. TSA began rolling out its Credential Authentication Technology (CAT-2) readers in 2023, which verify IDs and boarding passes simultaneously without requiring paper printouts or separate agent scanning. As of early 2026, CAT-2 readers are installed at all 25 of the TSA's busiest checkpoint locations. The agency's five-year modernization roadmap, outlined in its 2025 annual report, includes expanded biometric screening that could eventually replace standard ID checks entirely for enrolled travelers.