Section 423.906 - General payment provisions(a)Regular Federal matching. Regular Federal matching applies to the eligibility determination and notification activities specified in § 423.904(a) and (b) .(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- (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. 70 FR 4525 , Jan. 28, 2005, as amended at 73 FR 20509 , Apr. 15, 2008