The purpose of this transmittal is to inform you that effective October 1, 2026, DC Medicaid Managed Care Plans (MCPs) shall cover patient stays in Institutions for Mental Disease (IMD) for enrollees aged 21-64 years for up to sixty (60) days rather than only the first fifteen (15) days. This transmittal supersedes Transmittal 19-31 (rev), issued on June 23, 2022.