I move around a lot and have run into all kinds of weirdness when it comes to CPAP stuff. Any time you establish a new doc, if your CPAP prescription is more than 1-2 years old you need to do another sleep study, so I think I've done 6 different sleep studies over the years. The other thing to remember about CPAP is that it's not just the machine, you have to get replaceable supplies - masks, air tubes, etc every so…
I also learned how to adjust my machine manually because it was taking way too long to schedule new sleep doctor appointments and then appointments with the DME provider…I shouldn’t have to wait 6 months to a year in order to to get quality sleep.
I will never understand why a prescription for my BiPAP or my glasses is required. It is all pointless bureaucracy.