Connecting at Denver airport: short layovers, the train to the gates and customs

Denver is one terminal with three concourses, A, B and C, all beyond security and linked by an underground train. On a domestic connection you stay airside and ride the train. The airport itself says minimum connection times depend on your itinerary and airline, and tells you to ask your airline. International arrivals are different: every one clears customs at Denver, collects bags, rechecks them and goes back through security.

How much time does the airport say you need?

Denver's airport doesn't set a connection time. In its words: minimum connection times depend on your itinerary, your airlines and your individual circumstances, so contact your airline for guidance on your trip.

What the airport does publish helps you judge a short layover:

• Train: the trip from the terminal to the farthest concourse, C, is less than ten minutes.
• Walking to gates: the airport estimates roughly 5 to 15 minutes from security to the gates, depending on the gate, including the trip to the concourse.

On one ticket, the airline sold you a connection that meets its minimum and must rebook you if you miss it. Read is a 1-hour layover enough?

Moving between concourses

• The underground train links the terminal and the A, B and C concourses. Stations are in the center of each concourse, so gates at the ends of a concourse take longer to reach.
• A gates on foot: a bridge north of the security checkpoints leads to the A gates. B and C are reached by train.
• Changing concourses on a domestic connection means riding the train between concourses, inside security.

Arriving from another country

International flights arrive at the A gates. The airport's own steps for connecting:

1. Get off at the A gates and follow the signs to US Customs and Border Protection in the main terminal.
2. Clear immigration and customs.
3. Recheck your bags just outside the customs area. Airline staff will direct you.
4. Go through TSA security in the main terminal.
5. Take the train to your connecting gate at the A, B or C concourse.

All connecting passengers from international flights must clear security again, even when the final destination is another US city. Baggage carts are free in the customs area. Read international to domestic connections.

What's changing in 2026

• Construction in the main terminal: the south bridge between the east and west sides of Level 6 is closed and will reopen before Thanksgiving 2026. Use Level 5 to cross. This matters if you have to go back through security.
• New checkpoint: the East security checkpoint opened in August 2025, one of the two on Level 6.
• Gates are being reassigned as airlines move. Follow your boarding pass and the signs.

Follow the first flight

Add both flights to FlyingOver before you travel. You'll follow the first flight offline and see its estimated arrival, and with Premium, connection guidance shows whether your layover looks comfortable, whether you need to keep moving or whether you should go directly to the gate.