OBJECTIVES: Lisdexamfetamine dimesylate (LDX) 50 and 70 mg demonstrated efficacy in terms of reduced binge eating days per week in adults with moderate to severe binge eating disorder (BED) in 2 randomized control trials (RCTs). This analysis aimed to determine the budgetary impact of introducing LDX for the treatment of BED in the United States (US). METHODS: A 1-year budget impact analysis from a US health care payer’s perspective was performed. The patient population in the budget impact analysis was treated and diagnosed BED patients aged 18 years and older in the US. It was estimated that 17.5% of the budget impact patient population was treated with LDX in the first year of use. The base case analysis assumed a 12-week course of treatment, based upon RCTs’ treatment duration. The model considered health care utilization costs, drug costs and costs of adverse events. Inputs in the model were obtained from literature, trial data and an epidemiology survey. RESULTS: Based on the inputs and assumptions, the total direct budgetary cost of treating BED within the adult US population, without LDX is estimated to be $241,699,596 over a 1-year time frame. If LDX were to treat 17.5% of the market, then the expected total budget would increase to around $242,768,676 which would be primarily due to the drug cost; however, there would be health care utilization costs savings of around $2,257,096. Introducing LDX would imply incremental average per member per year cost by $0.004. CONCLUSIONS: The budget impact of treating BED with LDX is modest; additional scientific evidence on the long-term economic burden of BED and the long-term efficacy of LDX therapy would help better understand the budgetary effect of LDX in BED.