American Airlines quietly extends AAdvantage mileage expiration by 6 months

It's a big day for American's AAdvantage loyalty program — but there's some last-minute news that's sure to excite some infrequent flyers.

The Fort Worth-based carrier is changing its mileage expiration policy effective on March 1, giving flyers 24 months to keep their miles alive. The updated policy change was first published in American's updated terms and conditions, and a carrier spokesperson later confirmed the move to TPG.

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Before the revamped AAdvantage program launched, travelers would have 18 months, or a year and a half, to earn or redeem miles before they expired.

American is permanently extending the expiration window by six months, as it seemingly tries to give members move time to engage with the loyalty program.

Going forward, any earning or redemption activity within 24 months will keep your miles active, and reset the 2-year counter. This includes earning miles from an American or partner-operated flight, as well as with the airline's hotel, car rental, telecommunications and other service providers that offer AAdvantange miles for completing a transaction.

Alternatively, if you're a primary cardholder of an AAdvantage cobranded credit card, you won't be subject to a mileage expiration while the account is open. If you ultimately decide to close the account, you'll have either four months from closure or 24 months from the last activity date, whichever is later, to reset the expiration date.

The only other exception to American's expiration policy is for AAdvantage members who are under the age of 21. Children and young adults won't be subject to the 24-month activity requirement until they hit their 21st birthday. Then, they'll have two years to accrue some activity before their miles are expired.

If your miles do end up expiring, you can pay to have them reinstated by paying a reactivation fee within 24 months of mileage expiration. You can go to aa.com/reactivatemiles to see your offer, and note that a maximum of 500,000 miles may be reactivated during any mileage activation transaction.

Interestingly, American is moving in the opposite direction of its Big 3 U.S. airline competitors — both Delta and United no longer expire miles. American, on the other hand, is giving members six more months to earn or redeem their miles before they expire, which could increase its liability on unused miles. Hopefully, that won't translate to less lucrative redemption rates down the line.

Altogether, American's new expiration policy is only one aspect of the revamped AAdvantage loyalty program that launched on March 1. The new program includes a revamped elite-status scheme, which replaces the confusing flights, segments and dollars metrics with one new currency, called Loyalty Points.

Further, American is also making updates to the complimentary upgrade process, which are sure to be exciting to lower-tier elites.

For more about the revamped program, check out of TPG's comprehensive guide.