Yes, American Airlines AAdvantage miles do expire, but the policy is relatively generous compared to some competitors. In 2026, miles expire after 24 months of account inactivity. "Inactivity" means you haven't earned or redeemed a single mile within a two-year window. To keep your miles alive, you don't necessarily have to fly; any activity—such as making a small purchase through the AAdvantage eShopping portal, dining at a partner restaurant, or using a co-branded credit card—will reset the 24-month clock. Notably, for AAdvantage members under 21 years of age, miles do not expire at all. Additionally, if you hold an active American Airlines credit card, your miles are protected from expiration regardless of your flying frequency. If your miles do happen to expire in 2026, American allows you to "reinstate" up to 500,000 miles for a reactivation fee, provided you do so within 24 months of the expiration date.