How can I prevent my miles from expiring?
Just accumulate or redeem miles at American or with an AAdvantage member at
At least once every 18 months. We will automatically extend your mileage
Due date 18 months from the date of your most recent activity.
Your wallet shows how many miles you have and the earliest date
they could expire
You must earn or redeem the miles before the due date. Since you accumulate miles for flights the day you take them, not the date you buy the tickets, you should fly before the miles expire, not just make a reservation.
However, anything that gains or redeems miles is enough to prevent them from expiring. There are many ways to earn some miles, including shopping and restaurants, other purchases, credit cards, car rentals, hotels, etc. There are some programs that provide miles to conduct opinion surveys; These could be a free option, although you would have to check the fine print to see when the miles are credited and how much you should do to get them.