Educational Tool Only
This calculator provides a general eligibility assessment based on published ASMBS and NIH criteria. Actual surgical eligibility requires a full medical evaluation including health history, comorbidities, and surgeon assessment. This calculator is for general educational purposes only. Always consult a qualified bariatric surgeon.
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What the Eligibility Criteria Mean
The BMI thresholds for bariatric surgery eligibility were established by the NIH in 1991 and have been refined by ASMBS since. They represent the point at which the documented risks of obesity exceed the documented risks of surgery for most patients.
BMI 40+ — Standard Eligibility
A BMI of 40 or higher (previously called "morbid obesity") meets the primary threshold for bariatric surgery eligibility regardless of comorbidities. At this BMI level, the risk of obesity-related mortality and morbidity is considered sufficient to justify surgical intervention on its own.
BMI 35–39.9 with Comorbidities
A BMI between 35 and 39.9 meets eligibility criteria when accompanied by at least one significant obesity-related comorbidity. Type 2 diabetes, high blood pressure, sleep apnea, and joint disease are the most commonly recognized qualifying conditions. The comorbidity must be documented and clinically significant.
BMI 30–34.9 — Metabolic Surgery Consideration
Increasingly, ASMBS and international societies support consideration of metabolic surgery for patients with BMI 30–34.9 who have type 2 diabetes or metabolic syndrome that is inadequately controlled with medical management. This is not universally covered by insurance but is recognized in current clinical guidelines.
Next step: If you meet the eligibility criteria, the next step is a consultation with a bariatric surgeon at an accredited bariatric center. See the Before Surgery guide for what to expect at your first consultation and the Procedure Comparison page to understand your options.