Large gaps exist in the capacity of the US medical system to participate meaningfully in childhood obesity-prevention efforts and to meet the treatment needs of obese children. Current primary care practice for the prevention and treatment of childhood obesity often varies from evidence-based recommendations. Childhood obesity specialists have partnered successfully with schools of medicine, professional societies, and other organizations to collaboratively engage with primary care providers in quality improvement for obesity prevention and treatment. This review and commentary targets 2 audiences. For childhood obesity experts and their organizational partners, methods to support change in primary practice and the evidence supporting their use are outlined. For primary care providers and non-obesity specialists, effective strategies for changing practice and the potential benefits of addressing childhood obesity systematically are discussed.