I would think you would have asked yourself these questions, and answered them (the internet is very useful for such research) before making blanket claims about Medicare. I’ll help a little; private providers wishing to accept Medicare patients/payments apply at the state level to private contractors who accept applications and monitor compliance to performance regulations. Most Medicare providers (private businesses) also have non-Medicare patients and have to maintain staff to sort through the many insurance plans to decide if you can get the treatment your doctor recommends and to bill the right source, as well as people to contend insurer refusals to pay bills, a common practice among insurers, who formally regard paying your medical bills as “medical losses”. Medicare, nope, paying your bills doesn’t hurt their bottom line, bonuses, stock prices, their only concern is fraud.