What to Expect at the TSA Body Scanner

What Is the TSA Body Scanner?

The body scanner at TSA security checkpoints is officially called an Advanced Imaging Technology (AIT) machine. Most airports use the millimeter wave scanner, which looks like a large upright cylinder or box with glass panels. Some older airports may still use backscatter X-ray machines, though TSA phased most of those out.

The millimeter wave scanner uses non-ionizing radio waves (the same type used by 5G networks) to create a generic, cartoon-like outline image of your body. It cannot see inside your body and is not a medical X-ray.

What the Scanner Sees

The scanner detects objects on your body that differ from the surrounding tissue — metal, plastic, ceramics, liquids, and some fabrics. It generates a generic outline of a human body and marks any anomalies with a yellow box indicating their location.

Critically: the scanner does not produce a photo-realistic or anatomically explicit image of you. TSA replaced the original scanners (which did produce detailed body images) with the current generic-outline system specifically because of privacy concerns. The image shown on the screen is essentially a featureless body diagram with markers on it.

The screen showing the image is viewed by a remote TSA officer, not by the agent standing at the machine with you. Some machines are fully automated and flag anomalies without a human reviewing the image at all.

Step-by-Step: What Happens at the Scanner

Step 1: Prepare

Before stepping into the scanner, remove everything from your pockets. Everything. Even paper and soft items can trigger a false positive. Your phone, wallet, keys, gum, coins — all of it goes in your bag or the bin before you approach the scanner.

Step 2: Enter the Machine

A TSA agent directs you into the scanner when it's ready. Step into the indicated position on the floor (there are usually yellow footprint markers). Face forward.

Step 3: Raise Your Arms

Raise both arms above your head with elbows bent, as directed by the agent or the displayed instructions. This is the standard pose — feet shoulder-width apart, arms up.

Step 4: The Scan

The scan takes about 5-7 seconds. You may hear a slight hum or nothing at all. You don't feel anything — no radiation, no heat, no physical sensation of any kind.

Step 5: Step Out

The agent directs you to step out of the machine. If the scan was clear, they'll wave you through to collect your belongings. If the machine flagged something, they'll direct you to a separate area for additional screening.

What Triggers the Scanner

Common triggers that cause the scanner to flag an area:

• Forgotten items in pockets (even paper)
• Underwire in bras
• Thick waistbands or heavily seamed clothing
• Medical devices (insulin pumps, stomas, ostomy bags)
• Body jewelry
• Hair accessories with metal
• Compression bandages
• Sweat patches or medical patches
• Prosthetic limbs

Many of these triggers are perfectly fine — the scanner just can't distinguish between a medical device and a concealed item, so it flags the location for a human agent to investigate.

What Happens If You're Flagged

If the scanner flags something, a TSA agent will direct you to a secondary screening area. They'll tell you which area of your body was flagged and ask what's there. In most cases, you can explain — "I have an insulin pump on my left hip" or "I forgot I have a hair clip" — and they'll verify it and clear you.

If the agent can't verify by visual check alone, they'll do a targeted pat-down of the flagged area. This involves a gloved agent patting the specific location with the back of their hand. It's not a full-body pat-down unless the entire body scan was unclear.

Can You Opt Out of the Body Scanner?

Yes. You have the right to opt out of the body scanner and request a full pat-down instead. Simply tell the agent "I'd like to opt out" before stepping into the machine. Be aware that the pat-down is more invasive than a targeted secondary screening — it covers your entire body including sensitive areas — and takes longer. Most passengers who opt out do so for medical reasons (pacemakers, implanted devices) or personal preference.

Medical Devices and the Scanner

If you have an implanted device (pacemaker, defibrillator, insulin pump, etc.) or wear a medical device, inform the TSA agent before screening begins. You may be directed to opt out of the scanner or you may be cleared to go through — it depends on the device. The TSA Cares helpline (1-855-787-2227) can answer device-specific questions before your trip.

Is the Body Scanner Safe?

Millimeter wave scanners use non-ionizing radiation — the same type as radio waves and visible light. They do not emit X-rays. The safety profile is well-established. If you're pregnant, have concerns, or simply prefer not to use it, you can always opt out for a pat-down.

TSA PreCheck Passengers

If you have TSA PreCheck, you typically go through a metal detector rather than a body scanner. This is one of the benefits — faster, simpler, no arms-raised pose required.