To upgrade to First Class on American Airlines, start with an eligible ticket (basic economy usually doesn’t qualify). You can request an upgrade online, in the app, or at check-in. Options include using AAdvantage miles, systemwide upgrades (for elite members), or paying cash if the airline offers it. Complimentary upgrades may clear for elite status flyers on domestic flights. If no seats are available when you request, you can join a waitlist and hope it clears before departure. Higher status and booking higher fare classes improve your chances of getting an upgrade.