The MA Department of Public Health’s Bureau of Substance Addiction Services (BSAS) and RIZE Massachusetts are supporting ICH to evaluate Mobile Methadone Programs (MMPs), which have been launched across Massachusetts to expand access to opioid use disorder treatment. ICH is conducting a mixed-methods evaluation to understand program implementation, service reach, and client outcomes, using electronic health record data and interviews with staff and clients. The evaluation will provide BSAS with actionable insights into how MMPs function compared to traditional clinics. The evaluation findings will help BSAS refine its understanding of the mobile model and identify priorities for future funding, policy development, and program improvement.