OBJECTIVES: Bariatric surgery for the treatment of severe obesity (BMI≥40) in US adolescents is becoming more common, but data on cost-effectiveness are limited. Our analysis aimed to assess the cost-effectiveness of bariatric surgery for adolescent obesity. METHODS: A state-transition model was constructed to compare two strategies: standard management and bariatric surgery. In standard management, patients remained at their initial BMI over the follow-up duration. In the surgery strategy, patients received Roux-en-Y gastric bypass or sleeve gastrectomy. They faced risks of perioperative mortality and complications, as well as an initial decrement in quality of life, but also experienced quality-of-life improvements associated with weight loss. Cohort demographics (mean age 17; 75% female; initial BMI 53), surgery-related transition probabilities, and the time horizon (three years) were based on the Teen-LABS study (Inge, NEJM