The Walmarts or just about any other pharmacy chain can get prescriptions in their system forwarded to just about any of their stores that have a pharmacist. Of course that only works when you have one of their stores close by. For example in Valdez, AK, the nearest WM or other chain drug stores is only 285 miles close. Also, Canada will present some real problems. We use Express Scripts and get our 90 day renewals just before leaving. That requires some planning, but we've been doing it since 2006.