The SMARTer trial will be a three-arm, randomized controlled non-inferiority trial that compares the optimized, adaptive SMARTer intervention, fixed DPP, and Self-Guided (Control). The trial will address whether a scalable, stepped-care intervention can stand up to gold-standard DPP by achieving comparable weight loss at a lower cost. Alongside evaluation of clinical non-inferiority, a comprehensive economic evaluation will inform relative affordability. Cost information is important to inform treatment policy and change standard of care, but is sorely lacking for behavioral interventions. The SMARTer intervention reduces costs by initially offering minimal intervention to all and stepping up to offer more costly treatment components only to non-responders who fail to attain the target weight loss. A rigorous economic evaluation planned and designed alongside the SMARTer trial will provide an accurate, robust head-to-head comparison of costs, cost-effectiveness, and projected lifetime health care costs between the three arms.