In August 2018, Health Management Associates (HMA) recognized the need to educate and engage other justice system stakeholders to support jail MAT implementation among key county partners and stakeholders. HMA established an in-person learning collaborative model across the state with six targeted stakeholder groups: probation, adult collaborative courts, youth/dependency courts, public defenders, district attorneys, and human services/child welfare. More than 1,500 persons from these stakeholder groups were trained under State Opioid Response (SOR) I. Under SOR II, the project operated two learning collaboratives that addressed MAT access issues identified in SOR I justice-related projects and built on the successful strategies engaged in the Jail MAT project: county child welfare systems, including dependency courts and juvenile probation, and special populations focusing on persons with co-occurring substance use disorder (SUD) and serious mental illness (SMI) outside of incarceration. There were 13 Child Welfare teams and 5 Special Populations teams representing 14 county teams at the intersection of SUD, justice, and child welfare systems. County teams received targeted education and training about opioid addiction and treatment in county criminal justice and child welfare systems and worked on system collaborations, resource alignment, system mapping and gap analysis. Additional optional workgroups (Plans of Safe Care and Child Welfare Data) were convened with the aim of enhancing processes, sharing best practices, and leveraging multi-county input to inform state and county decisions.