ORDAirport Guide

Changing between United or American and Delta at O'Hare

Delta flies from Terminal 5, United from Terminals 1 and 2, American from Terminal 3. Bus and train routes, and what only your airlines can answer.

The white steel arches and skylights of the Terminal 1 concourse at O'Hare, seen from below.
Concourse C, Terminal 1

Changing between Delta and United or American at O’Hare means changing terminals, and Terminal 5 is the one you can’t walk to. Delta is in Terminal 5, United in Terminals 1 and 2 and American in Terminal 3. Terminals 1, 2 and 3 join on the secure side, so a change that includes Delta takes the Terminal Transfer Bus or the Airport Transit System. Our connections page lists the transfers the airport publishes.

Your route, by pair

The bus keeps you past security and runs every 15 minutes from 11:30 a.m. to 9:30 p.m. The train runs at any hour, every 3 to 5 minutes at peak times. The ride takes about 10 minutes end to end from Terminal 1. You exit security to board it and clear a TSA checkpoint where you arrive.

Your change By bus By train
United in Terminal 1 to Delta Gate C18B to Gate M13 Ride to Terminal 5, clear Checkpoint 10
United in Terminal 2 to Delta Walk to Terminal 1 or 3, then board at Gate C18B, G17 or K20 Ride from the Terminal 2 station to Terminal 5, clear Checkpoint 10
American in Terminal 3 to Delta Gate G17 or K20 to Gate M13 Ride to Terminal 5, clear Checkpoint 10
Delta to United in Terminal 1 Gate M13 to Gate C18B Ride to Terminal 1, clear Checkpoint 1, 2 or 3
Delta to United in Terminal 2 Gate M13 to Terminal 1 or 3, then walk Ride to Terminal 2, clear Checkpoint 5
Delta to American in Terminal 3 Gate M13 to Gate G17 or K20 Ride to Terminal 3, clear Checkpoint 6, 7, 7A or 8

Bus riders need a boarding pass for a same-day flight from the terminal they ride to, and the bus is for connecting passengers only. The airport’s bus page lists stops in Terminals 1, 3 and 5, none in Terminal 2.

When the bus isn’t running

Outside the bus’s hours, the train is the only route, and the checkpoint at the far end has to be open. The latest listed closing is 11 p.m. in Terminals 1 and 2 (Checkpoints 1 and 5) and 10:30 p.m. in Terminal 3 (Checkpoint 7A). Terminal 5’s Checkpoint 10 is listed open 24 hours. From 11 p.m. to 3:15 a.m., it’s the only checkpoint the airport lists as open.

The airport says its hours can shift with the day’s activity and asks you to check with your airline. If the checkpoint at the far end is shut, the airport’s pages give no other route. Our connection time guide lists every checkpoint’s hours.

Bags and screening: what the airport says

For a domestic change between two airlines, the airport’s connecting page says only to contact your airlines. It doesn’t say whether your bag moves from one airline to the other, so ask at check-in whether it’s checked through to your last stop.

If you land on Delta from outside the U.S., the rules differ. Unless you arrive from a preclearance airport, the airport says you claim every bag and clear customs. Bags checked through to your final stop go to the recheck counters directly outside the customs area. If they aren’t checked through and your next flight is United or American, you can recheck with an airline employee right after customs. Our Terminal 5 arrivals guide also covers the passport lines.

On screening, the airport’s connecting page says all connecting passengers must go through TSA screening. Its international traveler page says passengers arriving from a preclearance airport can take the Terminal Transfer Bus to Terminals 1, 2 or 3 without exiting security and getting rescreened.

What only your airlines can answer

  • Your gate. Ask your airline, which holds your flight information. The United and American connection guides cover each airline’s own terminals.
  • How much time your ticket allows. Ask your airlines, because the airport publishes no minimum connection time.
  • Separate tickets. The airport doesn’t address them, and the bus needs the second flight’s boarding pass in hand.
  • Wheelchair help on the transfer. Each airline coordinates its own, and the airport says that service can help you travel to or transfer between gates. Our accessibility page lists the airport’s contacts.

Sources