23 Miss. Code. R. 207-2.4
A state is not required to pay for any expenses related to payment for deductibles, coinsurance, or co-payments for Medicare cost sharing for dually eligibles that exceed what the state's Medicaid program would have paid for such service for a beneficiary who is not a dually eligible. When a state's payment for Medicare cost-sharing for a dually eligible is reduced or eliminated, the Medicare payment plus the state's Medicaid payment is considered payment in full; and the dually eligible cannot be billed the difference between the provider's charge and the Medicare and Medicaid payment. Medicare is the primary payor for dually eligible recipients, and providers are obligated to comply with the requirements covering the coordination between the two programs. Persons eligible for Medicare and Medicaid are entitled to all covered services available under both programs, but a claim must be filed with Medicare, if Medicare covers the service.
23 Miss. Code. R. 207-2.4