This pragmatic, cluster-randomized trial will evaluate whether a comprehensive CalAIM-aligned care model consisting of Enhanced Care Management, selected Community Supports, Transitional Care Services, and residential care coordination improves population health outcomes among high-risk Medi-Cal managed care members in California compared with usual CalAIM service delivery. The intervention is intended to improve continuity of care after discharge, reduce potentially avoidable utilization, increase successful linkage to outpatient and social supports, and improve community tenure and patient-reported outcomes.

California Advancing and Innovating Medi-Cal (CalAIM) initiative emphasizes person-centered care, integration across medical and social services, and support for members with complex clinical and social needs. Within this framework, Enhanced Care Management provides high-touch community-based care management, while Population Health Management requires Transitional Care Services to support members through discharge and follow-up. Community Supports may include medically appropriate substitute services such as recuperative care, short-term post-hospitalization housing, and supports related to nursing facility transition or diversion to assisted living and other community settings (Source: Department of Health Care Service (DHCS) Population Health Management (PHM) Policy Guide, DHCS Transitional Care Services (TCS) for Medi-Cal Members with Long-Term Services and Supports (LTSS) Resource, DHCS Community Supports Fact Sheet).

The study will prospectively compare two implementation approaches at the cluster level. Clusters assigned to the intervention will deliver a structured, comprehensive care bundle, including an assigned Enhanced Care Management (ECM) care manager, a discharge-transition workflow, medication-reconciliation support, timely ambulatory follow-up, community-support referral and activation, and residential stabilization or transition coordination, where indicated. Control clusters will continue usual CalAIM operations without the enhanced standardized bundle. The hypothesis is that comprehensive integration of these elements will reduce 30-day readmissions and emergency department utilization while improving community stability and total cost of care.

Inclusion Criteria:

• Adult Medi-Cal managed care member in California.
• Identified as high-risk for poor outcomes based on plan stratification or qualifying CalAIM criteria.
• Eligible for ECM and at least one of the following: Transitional Care Services, Community Supports related to post-acute recovery, housing/residential stabilization, or nursing facility transition/diversion.
• Recent discharge or active transition from hospital, emergency department, skilled nursing facility, post-acute facility, recuperative care, assisted living, residential behavioral health setting, or other qualifying level-of-care transition.
• Able to provide informed consent, or eligible for waiver/alteration of consent if approved for cluster-level pragmatic implementation research.

Exclusion Criteria:

• Enrollment in hospice or expected survival less than 6 months at the time of the index episode.
• Long-term custodial institutional placement without an anticipated community transition plan.
• Current incarceration or detention is preventing intervention delivery.
• Previous enrollment in this study during the same observation window.
• Any condition that, in the investigator's judgment, makes participation infeasible or data interpretation unreliable.

De-identified aggregate study findings will be disseminated in publications and presentations. Participant-level data may be made available only pursuant to data use agreements, HIPAA compliance requirements, Medi-Cal data restrictions, and institutional approvals.