I just used old passes this past Feb. and if the tickets have a magnetic strip on them they will just go through the turnstile - even if they are the paper kind. If they are the real old ones with the date stamped on the front, you hve to turn them in at guest relations and they issue new tickets which were the paper kind with a bar code on the back. I was lucky this past trip, I had enough days left over from past trips that I didn't need to buy a pass for myself however, they did tell me when I called prior to leaving for FL that the passes would not be good at any park that wasn't open when the original pass was bought. When I exchanged my old passes for new ones the man never said anything about where I could use them. We didn't plan on going to animal kingdom so I never tried it but I really think that the new passes( which said one day hoppers on them) would have been good anywhere. It is a much better deal to use the days then upgrade because of the price difference, IMO. HTH! Chris.