ELIGIBILITY GUIDE · 7-MIN READ · UPDATED SEP 2026
Bariatric Surgery Requirements Explained: BMI, Health Conditions and Age
BMI thresholds, comorbidities, age limits, psychological readiness — the complete eligibility checklist most clinics won’t share upfront.
By Dr. Alejandro López, MD · Bariatric Surgeon · Tijuana · Guadalajara · Puerto Vallarta
The Short Version
- At ALO Bariatrics we accept patients from BMI 30+ — aligned with 2022 ASMBS/IFSO guidelines.
- BMI 30–34.9 with diabetes, hypertension, sleep apnea, or metabolic syndrome qualifies.
- BMI ≥ 35 qualifies on its own (no comorbidity required).
- Age range: typically 18–65 (extended to 70 for healthy patients case-by-case).
- Psychological clearance + commitment to lifelong follow-up are non-negotiable.
“Am I a candidate?” is the single most common first question we get. The answer used to be straightforward: BMI 35 with comorbidities, or BMI 40 alone. That standard is now obsolete.
Updated 2022 ASMBS/IFSO guidelines lowered the threshold dramatically. At ALO Bariatrics we now accept patients from BMI 30 upward — especially when diabetes or metabolic disease is present. Thousands of patients who were told “you don’t qualify” under the old rules now do. For a fast self-check, see our candidacy quiz.
At ALO Bariatrics (Tijuana, Guadalajara and Puerto Vallarta, Mexico), Dr. Alejandro López, MD, FACS evaluates candidates from BMI 30, following the 2022 ASMBS and IFSO guidelines. Find your range in the table, then see how ALO evaluates candidates.
| Your BMI | Do you qualify? | What it depends on |
|---|---|---|
| 40 or higher | Yes | Qualifies regardless of other health conditions. |
| 35 to 39.9 | Yes | Qualifies on its own; no related condition required. |
| 30 to 34.9 | Yes, with a related condition | Type 2 diabetes, metabolic syndrome, hypertension or sleep apnea (2022 ASMBS/IFSO position). Evaluated case by case at ALO. |
| Below 30 | Not for surgery | Non-surgical options; talk to the team about the best path. |
Which procedure fits which BMI?
- BMI 30 to 50: gastric sleeve or gastric bypass; bypass is usually preferred with type 2 diabetes or significant reflux. See sleeve vs bypass.
- BMI 50 or higher, or severe long-standing diabetes: SADI-S or duodenal switch, because a sleeve or bypass alone may be insufficient.
- Age: 18 to 65 is the standard window; ALO extends to 70 case by case for healthy patients. Adolescents (14 to 17) only with a pediatric bariatric team and parental consent.
Find out in 2 minutes whether you qualify
Answer a short questionnaire. Dr. Alejandro López and his team review your BMI, health conditions and goals and tell you if you are a candidate and which procedure fits, with no obligation.
See if I qualify →The Core Eligibility Criteria
Three filters determine whether you qualify at ALO: BMI (now starting at 30), comorbidities or metabolic health, and readiness. All three need to align. A patient with high BMI but uncontrolled severe mental illness will be deferred. A patient at BMI 31 with type 2 diabetes is now a strong candidate — something that wasn’t true 5 years ago. We evaluate every case individually.
6 Requirements That Qualify You for Bariatric Surgery
Fact 1 of 6
BMI starts at 30 (updated 2022 guidelines)
At ALO, eligibility starts at BMI 30 when accompanied by type 2 diabetes, metabolic syndrome, hypertension, or sleep apnea. BMI 35+ qualifies on its own without comorbidities. BMI 40+ always qualifies regardless of other health factors. These updated thresholds follow the 2022 ASMBS/IFSO position statement that replaced the 1991 NIH criteria.
Fact 2 of 6
Obesity-related comorbidities
Common qualifying conditions: type 2 diabetes, hypertension, hyperlipidemia, obstructive sleep apnea, GERD, NAFLD, severe joint disease, PCOS, infertility. Each one independently lowers the BMI requirement to 35. See our companion article on diabetes and bariatric surgery for the highest-impact comorbidity.
Fact 3 of 6
Failed weight-loss attempts
Most clinics and all insurance plans require documentation of 6–12 months of structured non-surgical weight-loss attempts (medically supervised diets, behavior therapy, exercise programs, medications). For self-pay patients in Mexico, this requirement is less strict but still preferred.
Fact 4 of 6
Age range
18–65 is the standard window. Many centers (including ALO) extend up to 70 for healthy patients with comorbidities that improve with weight loss. Adolescent bariatric surgery (14–17) is FDA-approved for severe cases — see our guide.
Fact 5 of 6
Psychological readiness
Required: realistic expectations, no untreated severe mental illness, no active substance abuse, stable home environment. Most US insurance requires a mental-health clearance letter. Mexico-based clinics include a psychological assessment as part of pre-op evaluation.
Fact 6 of 6
Commitment to lifelong follow-up
Bariatric surgery isn’t a one-time event — it’s a permanent lifestyle change. You’ll need vitamin supplements forever, annual blood work, dietary discipline, and exercise commitment. Patients unwilling to make these long-term changes are typically deferred.
📌 BMI 30+ Now Qualifies (2022 ASMBS Update)
In 2022, the American Society for Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity (IFSO) updated their official position: patients with BMI 30–34.9 and type 2 diabetes or metabolic syndrome are now valid candidates. This was the biggest expansion of bariatric eligibility in 30+ years. At ALO Bariatrics, we follow these updated guidelines — many patients who were told “you don’t qualify” now do.
What Could Disqualify You
- Untreated severe mental illness (active psychosis, severe untreated depression)
- Active substance abuse (alcohol or drugs in the past 12 months)
- Active eating disorders (anorexia, bulimia within the past year)
- Severe cardiac or pulmonary disease that makes anesthesia high-risk
- Active cancer treatment (defer until in remission)
- Pregnancy (wait 18 months post-delivery, then qualify normally)
- Unrealistic expectations (surgery is a tool, not a cure)
- Inability to commit to lifelong follow-up and vitamin supplementation
Qualifying Through U.S. Insurance vs Self-Pay in Mexico
Through U.S. insurance
- Most plans still use the older thresholds: BMI 40, or BMI 35 to 39.9 with a related condition.
- 6 to 12 months of documented, supervised weight-loss attempts are usually required.
- A mental-health clearance letter and a pre-authorization process that can take months.
- Denials and appeals are common. See our insurance guide.
Self-pay at ALO Bariatrics in Mexico
- Eligibility from BMI 30 with a related condition, per the 2022 ASMBS/IFSO guidelines.
- No insurance approval; the pre-op evaluation, including a psychological assessment, is independent of any insurer.
- Documented diet attempts are preferred, not required.
- All-inclusive packages from $4,500 USD, with financing options. See pricing.
Not sure if you qualify?
Book a free 15-minute consult with our coordinator. We’ll review your BMI, medical history, and goals to give you a clear answer — no fluff, no pressure.
Frequently Asked Questions
How do I qualify for gastric sleeve or gastric bypass surgery?
You qualify with a BMI of 40 or higher, a BMI of 35 to 39.9 on its own, or a BMI of 30 to 34.9 with type 2 diabetes, metabolic syndrome, hypertension or sleep apnea. You also need to be roughly 18 to 65 (up to 70 case by case), psychologically ready, cleared by a pre-op medical evaluation and committed to lifelong follow-up.
What is the minimum BMI for bariatric surgery?
At ALO Bariatrics the minimum is BMI 30 when accompanied by diabetes, hypertension, sleep apnea or metabolic syndrome. BMI 35 and above qualifies without a related condition, and BMI 40 and above always qualifies. These thresholds follow the 2022 ASMBS/IFSO guidelines, not the old 1991 NIH cutoffs.
Can I qualify with a BMI of 30, 31 or 32?
Yes, if you have a related condition such as type 2 diabetes, metabolic syndrome, hypertension or sleep apnea. A patient at BMI 31 with type 2 diabetes is now a strong candidate under the 2022 guidelines. Without a related condition, surgery is usually not indicated below BMI 35.
Who qualifies for bariatric surgery, and what could disqualify me?
Candidates meet the BMI criteria, are 18 to 65 (extended case by case), have realistic expectations and can commit to lifelong vitamins, blood work and follow-up. You may be deferred for untreated severe mental illness, active substance abuse in the last 12 months, an active eating disorder, severe cardiac or pulmonary disease that makes anesthesia high-risk, active cancer treatment or pregnancy.
Is there an age limit for bariatric surgery?
The standard window is 18 to 65. ALO extends it to 70 for healthy patients with conditions that improve with weight loss, evaluated case by case. Adolescents aged 14 to 17 can be candidates for severe obesity, only with parental consent and a pediatric bariatric team.
Do I need insurance approval if I pay out of pocket?
No. Self-pay patients, including most patients who travel to Mexico, skip insurance approval entirely. The pre-op evaluation at ALO is independent of any insurance pathway, which is one reason patients choose Mexico: speed.
Do I need to lose weight or complete a supervised diet before surgery?
Everyone follows a pre-op liver-shrinking diet, typically 2 weeks, so the surgery is safer. Most U.S. insurers also require 6 to 12 months of documented supervised weight loss; for self-pay patients at ALO that documentation is preferred but not required.
Can I qualify if I am pre-diabetic?
Yes, especially if your BMI is 30 or higher and you are trending toward diabetes. Pre-diabetic patients often have some of the best outcomes because surgery can prevent diabetes from developing.
How do I know if I am psychologically ready?
Ask yourself honestly: are you mentally stable, have you addressed any disordered eating, and are you committed to lifelong changes? A psychological assessment is part of the pre-op evaluation, and if you are unsure, a session with a therapist trained in bariatric preparation is the best next step.
Will my BMI go down after surgery?
Yes. The average drop is 10 to 15 BMI points within the first year. A patient starting at BMI 45 typically reaches BMI 30 to 33 within 12 to 18 months. Bypass and SADI-S produce slightly more weight loss than the sleeve on average.
How do I find out for sure whether I qualify?
Complete the free online questionnaire: your BMI, health conditions and goals go to the medical team, a coordinator contacts you, and the final decision is made in the pre-op evaluation. No commitment is required to find out.
One last thing
Qualifying for bariatric surgery isn’t about hitting a magic number on a scale — it’s about whether your health, your weight, your mental readiness, and your life situation align. Most patients who think they don’t qualify actually do under newer guidelines.
Next steps: take our candidacy quiz, review bariatric surgery risks, or read how to choose a surgeon.
Medically reviewed by Dr. Alejandro López Ortega, MD, FACS
Bariatric surgeon board-certified by the Consejo Mexicano de Cirugía General, Fellow of the American College of Surgeons and founder of ALO Bariatrics (2011), with more than 20,000 bariatric surgeries. ALO Bariatrics operates in Tijuana, Guadalajara and Puerto Vallarta, Mexico; all-inclusive packages start at $4,500 USD. Updated: 2026-09-20.