New evidence of state variation in Medicaid payment policies for dual Medicare-Medicaid enrollees

Objective To develop the first longitudinal database of state Medicaid policies for paying the cost sharing in Medicare Part B for services provided to dual Medicare-Medicaid enrollees ("duals") and an index summarizing the impact of these policies on payments for physician office services. Data sources Medicaid policy data collected from electronic sources and inquiries with states. Study design We constructed a national database of Medicaid payment policies for the period 2004-2018, consolidating information from online Medicaid policy documents, state laws, and policy data reported to us by state Medicaid programs. Using this database and state Medicaid fee schedules, we constructed a Medicaid payment index for duals. This index represented the proportion of the Medicare allowed amount that physicians would expect to be paid from Medicare and Medicaid for a subset of physician office services (evaluation and management services) based on annual state payment policies and Medicaid fee schedules. Principal findings In 2018, 42 states had policies to limit Medicaid payments of Medicare cost sharing when Medicaid's fee schedule was lower than Medicare's-an increase from 36 such states in 2004. In the preponderance of states with these policies, combined Medicare and Medicaid payments for evaluation and management services provided to duals averaged 78 percent of the Medicare allowed amount for these services, reflecting relatively low Medicaid fee schedules in these states. In 2013 and 2014, physicians who qualified for the Affordable Care Act's Medicaid "fee bump" were paid 100 percent of the Medicare allowed amount for these services. Conclusions Medicaid programs vary across states and over time in their payments of cost sharing for physician office services provided to duals. Our database and index can facilitate monitoring of these policies and research on the consequences of policy changes for duals.