To get into an Amex Centurion Lounge, you must be on a departing flight leaving from a qualifying airport. You can enter the lounge up to three hours ahead of your departure time, as listed on your boarding pass. You can check in at the lounge's reception desk, but there is also a mobile check-in option.

For a standard departing flight, the general rule for American Express Centurion Lounges in 2026 is that you can enter no earlier than 3 hours before your scheduled departure time. This rule was implemented to combat overcrowding and ensure a premium experience for all cardmembers. However, if you are a connecting passenger with a layover, the policy is more generous; as of July 2026, connecting travelers can access the lounge up to 5 hours before their onward flight, provided they have a boarding pass for their next segment. You cannot use the lounge as an "arrival lounge" unless you have a confirmed connection later that day. It is also important to note that your "departure time" is based on the original scheduled time on your boarding pass; if your flight is significantly delayed after you have already entered the lounge, you are generally permitted to stay until your flight departs, but you cannot enter the lounge earlier than the 3-hour (or 5-hour) window relative to the new delayed time if you haven't checked in yet.