Be careful that you are not changing the original ticket. I made a change to an existing reservation and paid the expected change fee.New ticket number but same PNR. This occurred after the new policy went into effect.
Now need to cancel the trip and was told I’ll be charged a second change fee with any residual available for a future ticket.
Wish AA would make it easy to see what amounts I have on account for future use. Especially if changing ticket can result in double cancellation fees versus cancel and then new booking.