Bright Bodies is a high-intensity, family-based intervention for childhood obesity where children and their families meet twice per week for 3-6 months and engage in nutrition, behavior modification, and exercise classes. The intervention was found to lead to the biggest reduction in body mass index among U.S.-based childhood obesity interventions evaluated in the 2017 U.S. Preventive Task Force Report. In this study, we use a mixed methods approach to evaluate historical dissemination sites of Bright Bodies, optimize the Bright Bodies package, and disseminate it at three heterogenous sites (Maine, Alabama, and California) serving populations with racial and ethnic, rural-urban, and geographic diversity. The site in Maine is located in the Oxford Hills community at Stephen’s Memorial Hospital. Patients can be referred by their primary care doctor, and the program will launch October 2022.