42 CFR 423.906 - General payment provisions.
(b)Medicare as primary payer. Medicare is the primary payer for covered drugs for Part D eligible individuals. Medical assistance is not available to full-benefit dual eligible individuals, including those not enrolled in a Part D plan, for -
(1) Part D drugs; or
(2) Any cost-sharing obligations under Part D relating to Part D drugs.
(3) The effective date of paragraphs (b)(1) and (b)(2) of this section is January 1, 2006.
(c)Noncovered drugs. States may elect to provide coverage for outpatient drugs other than Part D drugs in the same manner as provided for non-full benefit dual eligible individuals or through an arrangement with a prescription drug plan or a MA-PD plan.