In 2006, six million beneficiaries who were eligible for both Medicare and Medicaid switched from Medicaid to Medicare Part D for coverage of their prescription drugs. This change led to an expanded role for Medicare in financing psychotropic medications for dual eligibles. A reduction in the number of plans serving these beneficiaries and an increase in utilization restrictions for some psychotropics since 2006 raise concerns about access to medications for dual eligibles with mental disorders and point to potential problems with adverse selection. To improve access for this population, Medicare might consider changes to its enrollment and risk-sharing systems.