This brief identifies the steps necessary to realize an integrated system of care, reviews two current approaches, and makes recommendations—including specifying policy reforms that would promote interagency collaboration, integration, service delivery, and improved outcomes for California’s children, both with and without disabilities. As a full commitment from the state administration is necessary to realize the proposed solutions at scale, this brief recommends the formation of a statewide interagency leadership council that has legitimacy, decision-making authority, and accountability across state and local policy and administrative levels. We also present recommendations for integrating California’s many child-serving agencies and organizations that simultaneously serve children and families into a “Whole System” approach.