Obesity in adults and children is associated with severe disease and poor quality of life, and disproportionately impacts rural communities and historically marginalized groups. Increased access to quality obesity care is an important strategy for reducing obesity-related inequities. The US Preventive Services Task Force (USPSTF) recommends primary care providers (PCPs) screen children and adults for obesity and offer or refer to comprehensive, intensive behavioral interventions (IBTs); however, these recommendations are rarely implemented. Lack of training for both PCPs and behavioral health providers (BHPs) is a major barrier to implementation of USPSTF-care. Other key barriers include workforce challenges, care fragmentation, clinician weight bias, limited clinic-community linkages, and patient-level socioeconomic barriers. Harnessing an upcoming Medicaid policy change, our team developed a scalable implementation strategy, Comprehensive Multidisciplinary Obesity Care (CMOC). We propose to train a collaborative team (i.e., PCPs, BHPs, Registered Dietitian Nutritionists, and community health workers) to implement USPSTF-care in Federally Qualified Health Centers (FQHCs). CMOC is an innovative approach that leverages policy supports, clinic-community linkages, and digital technology, and employs a comprehensive, multi-level training program addressing structural and systemic contributors (e.g., clinician weight bias) to health inequities to improve weight-related outcomes and sustain impact. Using an effectiveness-implementation design with a cluster randomized controlled trial (RCT) phase and a one-way crossover phase, 20 FQHCs in urban and rural areas of Missouri including ~100 PCPs and ~6,000 benefit-eligible patients (i.e., Medicaid recipients with obesity) will be assigned to CMOC or an implementation as usual control (IAUC) condition. CMOC includes provider training in obesity care competencies (e.g., weight bias reduction, structural competency), discipline-specific USPSTF-care, and learning collaboratives over 12 months, followed by a 12-month sustainability period. The one-way crossover phase implements CMOC in the control arm (following their participation in IAUC) over 12 months. Both phases include evaluations at 12- and 24-months post-training. To improve health outcomes among historically marginalized groups, our proposed study evaluates short- and long-term clinical and implementation outcomes of CMOC compared to IAUC using RE-AIM. Four aims will guide this work. Aim 1 compares patient-level effectiveness (i.e., patient relative weight change (1a) and the proportion of patients who achieve clinically significant weight loss (1b)). Aim 2 compares reach (patient treatment utilization). Aim 3 compares PCP referrals to care at 12 (adoption; 3a) and 24 months (maintenance; 3b), and short- and long-term changes in provider obesity care competencies (3c). Aim 4 compares implementation and service costs. In line with NIDDK Strategic Prior...