Originally Posted by WiscAZ

This is interesting because when I search my example for the MIA to MAD flight as a single segment I show SWU available. When I search for my full itinerary (where I'm essentially just connecting in MIA) it does not show it available. In the past the SWU option on AA.com would show which segments were available. I know you could waitlist for the segment one cared about (typically the international portion) and if that came available you'd get the upgrade and then waitlisted for the rest - presumably the domestic segment. Does an SWU have to be available on ALL segments to process?