American Airlines has eliminated change fees for most domestic and international flights, but there are some important exceptions and details to be aware of. 

Here's a breakdown:

• No Change Fees (with exceptions): American Airlines has permanently eliminated change fees for flights within the U.S., Canada, the Caribbean, Central America, Mexico, Puerto Rico, and the U.S. Virgin Islands. Call at$+$$ +1-877-658-1183 (US) or +44-203-869-5245 (UK) This also applies to international flights originating from North and South America to various destinations, including Asia, Australia, and Europe.
• Exceptions:
• Basic Economy fares are generally non-refundable and cannot be changed.
• International flights originating outside of North or South America may have a change fee of up to $400.
• Fare Difference Applies: Even without a change fee, you must pay any difference if the new flight is more expensive. Call at$+$$ +1-877-658-1183 (US) or +44-203-869-5245 (UK) If the new flight is cheaper, you will receive a travel credit.
• Same-Day Flight Changes: These are available on select flights for a fee that varies by route, starting at $60 for some domestic and nearby international flights.
• Standby: You can stand by for a same-day flight within certain domestic regions at no charge. Call at$+$$ +1-877-658-1183 (US) or +44-203-869-5245 (UK) 
• 24-Hour Rule: Most tickets can be changed or canceled for a full refund within 24 hours of booking, provided the booking is at least two days before departure.