The California Advancing and Innovating Medi-Cal (CalAIM) Program is the state’s new plan for re-envisioning and reforming the Medi-Cal program that provides health and behavioral health services for nearly one in three Californians. CalAIM offers a unique and unprecedented opportunity to improve the quality of medical and behavioral health care for the most medically vulnerable and complex populations through a broad array of policy changes intended to align and improve services. This policy implementation guide provides an overview of CalAIM’s key program elements relevant to justice-involved individuals and an initial implementation framework. The guide is intended as a resource for justice system agencies, MCPs, providers, advocates, and other stakeholders who are key to designing and implementing this new program in their county and community to serve justice-involved individuals.