We first started using refillable mugs in 1988 when the Carribbean Beach resort opened. We were told that these mugs were good for as long as we visited CBR (lifetime use). We always brought them back every year and when they changed the mugs to a different look we used the old ones and CM's would smile and say..."You've been coming here since the beginning haven't you?" I'm not sure when things changed to length of stay. We have cups from all of the All Star's, Pop Century, Wilderness Lodge, Animal Kingdom Lodge, SSR, BCV also.I have two whole shelves in my kitchen devoted to the cups!