How can I gain access to the Amex Centurion Lounge?

To gain access to an American Express Centurion Lounge, one must hold either an American Express Platinum Card, a Centurion Card, or be a guest of a cardholder. Upon arrival at the lounge, the individual must present their eligible credit card, a boarding pass showing a confirmed reservation for same-day travel on any carrier, and a government-issued ID. Holders of the Platinum Card can enter with up to two guests at no additional charge, while additional guests beyond this limit may be admitted for a fee per person. Centurion Card members have complimentary access for immediate family or up to two companions. Access is subject to capacity restrictions and typically begins three hours before the scheduled departure time of the guest's flight.