@bgilchr
Bill
Though not familiar with Rove6, I did some research on Medicare coverage.

Inogen, maker of Rove6 has a web page about Medicare and coverage. It appears you may need to rent instead of buy.

The information is very thorough, including what you need to provide from your provider.
https://www.inogen.com/oxygen-therapy/medicare-for-portable-oxygen-concentrators/
It also references Medicare oxygen supplies information:
https://www.medicare.gov/coverage/oxygen-equipment-accessories
On that page, it also mentions supplier of Durable Medical Equipment (DME) participate in Medicare.

Most of the references apply to Original Medicare (Part A & B). If you have a Medicare Advantage plan, you should contact the insurance company about any questions.

For original Medicare, the contact info is on this page:
https://www.medicare.gov/talk-to-someone
Have you talked to your provider about prescribing a Rove6 and the required documentation?