Originally Posted by aamilesslave

Since this is in the combined AA/US forum, I'll clarify that AA and US do things differently in this regards.

AA takes the change fee out of the ticket value and lets you apply the residual (e.g. 500 ticket - 200 change fee = 300 residual applied to new ticket)

US makes you pay the change fee and lets you apply the full value of the original ticket (e.g. 500 ticket, pay 200 change fee, apply 500 value to new ticket)

This is one area where I haven't seen an indication on how the new AA will go in the future (I could guess, but that wouldn't do much good).