Medicare Plan N

@InessaG960679 

The ONLY time a beneficiary would encounter them (and it is rare) is if the provider did not accept Medicare Assignment and they are deemed “non-participating” by Medicare.

This Medicare link describes the “non-participating” providers as well as what it means to be a provider that accepts assignment and the ones that work only on a contract basis and thus does NOT accept Medicare at all.

Medicare.gov - Does your provider accept Medicare as full payment? 

“NON-PARTICIPATING” Providers

From the link:  [copy/paste]

Some doctors, health care providers, and suppliers who don’t accept assignment still choose to accept the Medicare-approved amount for services on a case-by-case basis. These providers are called "non-participating."

If your doctor, provider, or supplier doesn't accept assignment:

• You might have to pay the full amount at the time of service.
• They should submit a claim to Medicare for any Medicare-covered services they give you, and they can’t charge you for submitting a claim. If they refuse to submit a Medicare claim, you can submit your own claim to Medicare. Get the Medicare claim form.
• They can charge you more than the Medicare-approved amount. In many cases, the charge can't be more than 15% above the Medicare-approved amount for non-participating healthcare providers. This amount is called "the limiting charge."

end copy/paste - there is more at the link ~

It may also be worth mentioning that some states have outlawed the practice of excess charges for Medicare in their state.  Last I checked (in mid 2025) these states were:  Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont.