I called the number on their site to find out more about Medicare coverage. There are some requirements: you have to have a neurological diagnosis, you shouldn't have had any assistive mobility device covered by Medicare in the last 5 years, and I believe there were a couple of other requirements.

Medicare coverage seems to vary by state, and it sounded fairly involved, at least for my state. I decided to call another time when I felt up to dealing with that much information. But apparently there is Medicare coverage.