SEA Gate Map: Concourses A to D, N and S Satellites

Clear security at any checkpoint: all concourses are connected past security. SEA posts live wait times for Checkpoints 1 to 6 on its website.

Checkpoints 1, 2 and 3 are closest to the south train loop (A, B and S). Checkpoints 4, 5 and 6 are closest to the north train loop (D, C and N).

Concourses A, B, C and D are linked, so you can walk or ride the train. The N and S Concourses are not connected to the other gates, so you must take the SEA Underground train to reach them. SEA says most trips through the terminal take two to five minutes. Its interactive map gives step-by-step directions with travel time.

The SEA Underground has three lines, each marked by its color on the station walls and signs:

• Blue Line (South Train Loop): S, B and A Concourses.
• Green Line (North Train Loop): N, C and D Concourses.
• Yellow Line (Terminal Shuttle): only two stops, the A and D stations. Get off after one stop, or you'll end up back where you started.

The Port says a train arrives every three minutes. A Station is across from Gate A3, B Station is down the escalators from Gates B20 and B21, D Station is across from Gate D2 and C Station is by Gate C11. The N and S stations are below their concourses.

If you are connecting, ignore the baggage claim signs: staff at a desk on the train level usually means you are about to leave the secure area.

SEA is short on gate space, so some flights park away from the terminal and you ride a bus to or from the plane. The Port calls this ground boarding.

The official map shows bus boarding points at B20 and B21, D20, the D Annex (D21 to D26), and near A20 and A21, D6 and D7, and S1. Gates D21 to D26 are on the lower level, and Gate D20 is for arrivals only from ground boarding flights. To meet someone landing at D20, wait on the escalator landing that leads down to the D train station near Gate D2. The D Annex, across from Gate D5, was built for bus boarding.

When a train loop is closed for maintenance, buses link the N and S Concourses instead.

The Port says almost every international airline flies from the S Gates or the south end of the terminal. Its airline directory lists most foreign airlines at the S Concourse. Delta uses Concourses A and B.

International arrivals clear customs at the International Arrivals Facility, east of Concourse A: passengers from the S Concourse cross an aerial walkway, and eight A gates connect directly through an international corridor. Alaska Airlines mostly uses C, D and N.

Each concourse shows its first and last gate, but not every number exists. Concourse A jumps from A14 to A20, and the S Concourse has no S13 or S14.

Some Concourse C gates carry a letter: C2A to C2H and C2N, C10A to C10F and C16A to C16F. On the official map, ten of them are shown as pairs (C2A/B, C10C/D…), and we list each letter so you can find the gate on your boarding pass. Concourse B also has B5A and B7A. Type the full gate from your boarding pass in the finder above.