What to do if you’re wrongfully billed for Medicare costs
If you’re among the 7.5 million people in the Qualified Medicare Beneficiary (QMB) Program , doctors, suppliers, and other providers should not bill you for services and items covered by Medicare, including deductibles, coinsurance, and copayments. If a provider asks you to pay, that’s against the law.
https://www.consumerfinance.gov/about-us/blog/what-do-if-youre-wrongfully-billed-medicare-costs/