Medicare and Medicaid Drug Payments for Medicare Only and Medicare/Medicaid Dual Eligible Populations

The availability of the Medicaid and Medicare Drug Payment data allows for improved investigation of drug usage and costs for the dual eligible (duals) population. The purpose of this study was to evaluate Medicare and Medicaid drug payments for the 2007 Part D enrolled Medicare population with primary emphasis on duals. Using the Medicare administrative claims and Medicaid Analytic eXtract (MAX) files from the Chronic Condition Data Warehouse (CCW), enrollment and claims information for Medicare and Medicaid were linked. Beneficiaries were classified as either Medicare only or dual eligible, and drug use and payment information was obtained. Total prescription drug costs and number of drug fills were evaluated, as well as the type of drugs paid by Medicare compared to Medicaid for duals. For the 9 million dual eligible beneficiaries, Part D total drug costs were $30 billion, and Medicaid total drug costs were $1.8 billion. The percentage of total drug cost covered by Medicare compared to Medicaid varied by state. Among duals, the therapeutic class with the highest utilization in both Medicare Part D and Medicaid files was central nervous system agents (115 million and 21 million drug fills respectively), the second highest utilization for Part D was cardiovascular drugs (99 million fills), and second highest for Medicaid was vitamins (6 million fills). Medicare and Medicaid prescription costs for these drug classes among dual eligible beneficiaries were $10 billion and $525 million, respectively, for CNS agents and $4 billion (Medicare) and $128 million (Medicaid) for cardiovascular drugs.