As the largest payer of mental health services in the United States, Medicaid programs have an opportunity to promote high-quality care for serious and persistent mental illnesses (SPMI) through the use of reimbursement strategies and policies that encourage the delivery of evidence-based practices (EBPs). These EBPs, which include pharmacologic, psychosocial, and physical health services, help beneficiaries with SPMI avoid costly institutional care, maintain employment, and engage in the community. However, few studies have examined the extent to which Medicaid beneficiaries with SPMI receive EPBs, and most of those studies have focused on Medicaid beneficiaries in a single state or smaller geographic area.