Sea-Tac Airport (SEA)
Seattle-Tacoma International Airport · Seattle, United States
Verified airport guidance · Last checked September 2026
Seattle-Tacoma International (SEA) is one terminal with six concourses — A, B, C, D, N and S — linked behind security by the SEA Underground train. International flights arrive at the International Arrivals Facility at the south end, where every passenger clears U.S. Customs and Border Protection, even when connecting.
International connections
Arriving from abroad, you collect your checked bags first, then go through U.S. passport control (CBP). After CBP, stay to the right to recheck your bags — Alaska and Delta agents help there; passengers on other airlines may need to exit and recheck at the ticketing level.
All connecting passengers then go through TSA screening. The International Arrivals Facility checkpoint is open 6:00 a.m. to 9:45 p.m.; outside those hours you exit and use a main checkpoint. After screening you're in Concourse A.
Immigration
CBP processing can take 60 minutes or longer at peak times (10am–3pm). The Port of Seattle recommends at least 2–3 hours for a connection after an international arrival; its arrivals page says at least three hours.
Source: Port of Seattle — International arrivals and passport control
Arriving from a Preclearance airport
Flights from U.S. Preclearance airports — including in Canada, Ireland, the Caribbean and the UAE — have already cleared U.S. passport control. You bypass CBP and TSA on arrival and go straight to your connection.
Source: CBP — Preclearance
Domestic connections
All gates are connected behind security, so between domestic flights you won't go through TSA again.
Source: Port of Seattle — User's guide to the SEA train (2020)
Getting between concourses
Concourses A, B, C and D are all connected — you can walk or take the train between them. The N and S satellites aren't connected to the other gates: you reach them only on the SEA Underground (Blue Line: S, B, A · Green Line: N, C, D · Yellow Line: A ↔ D). Trains run about every 3 minutes.
Source: Port of Seattle — All aboard the SEA Underground (2025)
Departing from SEA
Check in with your airline, then go through one of SEA's six TSA checkpoints — lanes and hours differ and can change. Until November 29, 2026, the free SEA Spot Saver lets you book a screening time at Checkpoint 4.
The Port's checkpoint page says to arrive 2 hours before departure for domestic flights and 3 hours before for international flights; another Port page counts those hours from boarding time. There's no U.S. exit passport control; CBP records departures from airline data.
Source: Port of Seattle — Security
Connection tips
- Bags first: at SEA you collect checked bags before passport control.
- Allow at least 2–3 hours after an international arrival.
- If you land after 9:45 p.m., expect to exit and re-enter through a main TSA checkpoint.
Getting around SEA
Where you can walk, and where you'll need a train or bus. Walking times are shown only where the airport publishes them.
| Between | Walk? | Other ways |
|---|---|---|
| Concourse A ↔ Concourse BSEA Underground (Blue Line) (after security) | Yes after security | SEA Underground (Blue Line) (after security) |
| Concourse B ↔ Concourse C | Yes after security | — |
| Concourse C ↔ Concourse DSEA Underground (Green Line) (after security) | Yes after security | SEA Underground (Green Line) (after security) |
| Concourse A ↔ Concourse DSEA Underground (Yellow Line) (after security) | No | SEA Underground (Yellow Line) (after security) |
| Concourse S ↔ Concourse ASEA Underground (Blue Line) (after security) | No | SEA Underground (Blue Line) (after security) |
| Concourse S ↔ Concourse BSEA Underground (Blue Line) (after security) | No | SEA Underground (Blue Line) (after security) |
| Concourse N ↔ Concourse CSEA Underground (Green Line) (after security) | No | SEA Underground (Green Line) (after security) |
| Concourse N ↔ Concourse DSEA Underground (Green Line) (after security) | No | SEA Underground (Green Line) (after security) |
| Check-in hall ↔ Concourse A | Yes before or after security | — |
| Check-in hall ↔ Concourse B | Yes before or after security | — |
| Check-in hall ↔ Concourse C | Yes before or after security | — |
| Check-in hall ↔ Concourse D | Yes before or after security | — |
Sources: Port of Seattle — All aboard the SEA Underground (2025) · Port of Seattle — Security
Airport map — SEA
SEA indoor map
Map data © Mapbox. Indoor maps are an experimental Mapbox feature. We don't draw walking routes.
We don't mark gates or checkpoints until we have verified locations for them.
Getting away from SEA
Official options, in no particular order. Times only where the operator publishes them.
Link light rail· about 38 min
From baggage claim, go up to the 4th floor and cross the skybridge to the parking garage level.
To downtown Seattle; trains every 8–10 minutes most of the day. A free Train-to-Plane shuttle runs 5 a.m.–midnight.
Source: Sound Transit — SEA Airport
Uber / Lyft (app rides)
3rd floor of the parking garage, stalls 1–34.
Rental car shuttles
Outside on the lower drive of the Baggage Claim Level, north and south ends (24/7).
Check fares and schedules with the operator before you travel.
Official resources
- SEA — Security checkpoints (opens in a new tab)
- SEA Spot Saver (until Nov 29, 2026) (opens in a new tab)
- SEA — International connections (opens in a new tab)
- SEA — International arrivals and passport control (opens in a new tab)
- Official airport website (opens in a new tab)
- SEA — Ground transportation (opens in a new tab)