Can You Use Your American Airlines AAdvantage Miles For Upgrades On Other Carriers?

American Airlines’ AAdvantage program is one of the most popular (and oldest) frequent flyer programs. While earning miles for flights, hotel stays, and everyday purchases is straightforward, many travelers wonder about the flexibility of these miles, particularly when it comes to upgrades on other airlines. Can AAdvantage Miles be used for upgrades on other carriers and if so, how?