Upgrades on American Airlines let you move from a lower cabin (like Main Cabin) to a higher one (Premium Economy, Business, or First) if space is available. You can upgrade using AAdvantage miles, systemwide upgrades (for elite members), complimentary elite upgrades on domestic routes, or by paying cash.
Priority depends on your elite status, fare type, and when you request the upgrade. Complimentary upgrades are common on domestic flights but rare on international routes. If seats aren’t available at booking, you can be placed on a waitlist and cleared closer to departure.
