Over the last 50 years, the number of inpatient psychiatric facilities in the US, mostly state-run hospitals, has sharply declined due to deinstitutionalization and Medicaid policies like the IMD Exclusion. Deinstitutionalization reduced state-run psychiatric beds by over 90% from 1955 to 2012. The IMD Exclusion further curtailed Medicaid reimbursement for large facilities, shifting treatment to community-based outpatient care. However, this has left many areas without adequate inpatient beds. Recent policy changes now allow Medicaid reimbursement for some short-term inpatient mental health and addiction services for adults aged 21-64 which could help address gaps.