For American Airlines AAdvantage members in 2026, the timeframe to claim missing miles depends on whether you were a member at the time of the flight. If you were already an active member, you generally have up to 12 months from the date of travel to request credit for a flight operated by American, American Eagle, or a partner airline. However, if you only joined the program after your flight, you can still claim miles for travel taken up to 30 days prior to your enrollment date. To file a claim, you typically need your 13-digit ticket number (starting with 001) and your flight details, which can be submitted via the "Request Flight Miles" section on the American Airlines website. It is important to wait at least 15 days after an international flight or 3 days after a domestic flight before filing, as it often takes this long for the system to process the data automatically. Keep in mind that "award tickets" (those booked with miles) are not eligible for mileage accrual, so you should only bother with the claim process for "revenue" (paid) fares to ensure your status-qualifying points and redeemable miles are correctly credited.