Free Shuttle and Transfers at O’Hare International Airport
Connecting travelers transferring to a different flight should keep in mind that there are four terminals at O’Hare International Airport – Terminals 1, 2, 3 and 5. Terminals 1, 2, and 3 are domestic terminals and are easily accessible from each another as all of them are connected. Connecting between those two terminals does not require clearing the security checkpoints. No shuttle buses are needed for connecting between domestic terminals.
To connect between Terminal 5 and any other terminals, passengers should use the Airport Transit System (ATS). If a passenger arrives on a domestic flight and needs to connect to an international one, they can take either ATS or Terminal Transfer Bus (TTB) from terminal 3 to Terminal 5. TTB has three pickup locations at gates G17, K20, and L24.
Passengers arriving on an international flight with checked luggage, need to pick it up and take them through customs again. The amount of time required to re-check the baggage differs and depends on the circumstances. You will need to go through customs and border control if you arrive on an international flight.