Medicare covers bariatric surgery, but only if you meet strict medical requirements and follow a specific approval process.

Medicare Part B will pay for weight loss surgery if your doctor documents that you have a body mass index (BMI) of 35 or higher with an obesity-related health condition, or a BMI of 40 or higher regardless of other conditions. You must also have tried medically supervised weight loss for at least six months before surgery, and your doctor must refer you to a bariatric surgery center that Medicare recognizes. The surgery itself — whether gastric bypass, gastric banding, or sleeve gastrectomy — is covered at the same rate as other surgical procedures: you pay your Part B deductible and then 20% of the approved amount.

The approval process takes time. Your primary care doctor sends your medical records to the bariatric surgery center, which reviews them and decides whether you meet the requirements. If the center approves you, Medicare reviews the case again before authorizing the surgery. This can take several weeks. Some Medicare Advantage plans (Part C) cover bariatric surgery under different rules, so if you have an Advantage plan, call the plan directly to ask what documentation your doctor needs to submit.

Key Takeaways

  • Medicare Part B covers bariatric surgery if your BMI is 35 or higher with an obesity-related condition, or 40 or higher without other conditions.
  • You must have tried medically supervised weight loss for at least six months before your doctor can refer you for surgery.
  • The bariatric surgery center and Medicare both review your case, and approval typically takes several weeks.
  • You pay your Part B deductible plus 20% of the approved surgical cost; the rest is covered by Medicare.
  • Medicare Advantage plans have their own coverage rules, so contact your plan to learn what it requires.

What BMI and health conditions Medicare requires

Medicare uses BMI as the starting point, but BMI alone is not enough. You must fall into one of two categories: a BMI of 35 or higher and at least one obesity-related condition, or a BMI of 40 or higher regardless of other health problems. Obesity-related conditions that Medicare recognizes include type 2 diabetes, high blood pressure, heart disease, sleep apnea, and osteoarthritis of weight-bearing joints.

Your doctor calculates your BMI from your height and weight. A BMI of 35 means you are roughly 60 pounds or more overweight if you are 5 feet 5 inches tall, or 70 pounds or more if you are 5 feet 10 inches tall — the exact number depends on your height. If you are not sure whether your BMI qualifies, ask your doctor to calculate it and tell you whether you meet Medicare's threshold.

The six-month weight loss requirement

Before Medicare will cover bariatric surgery, you must show that you tried to lose weight under medical supervision for at least six months. This does not mean you have to succeed — you have to try. Your doctor documents the visits, the weight loss plan discussed, and your weight at each visit. Some doctors use a registered dietitian or weight loss program to supervise this period; others manage it themselves in the office.

The six months must happen before your bariatric surgery center submits your case to Medicare. If you have already been seeing a doctor about weight loss, those visits may count toward the six months. Ask your doctor whether the weight loss work you have already done satisfies this requirement, or whether you need additional visits before a referral can be made.

How the approval process works

Once your doctor believes you meet Medicare's requirements, they refer you to a bariatric surgery center. Medicare maintains a list of recognized centers; your doctor should refer you to one on that list, because surgery at an unrecognized center will not be covered. The surgery center reviews your medical records, imaging, lab work, and weight loss history to confirm you meet the criteria.

If the surgery center approves you, it submits your case to Medicare for a second review. Medicare checks that the documentation is complete and that you truly meet the BMI and medical condition requirements. This review usually takes one to three weeks. Once Medicare approves the case, the surgery center schedules your operation. The entire process from referral to surgery date typically takes four to eight weeks, though it can be faster or slower depending on how quickly records arrive and how busy the center is.

What you pay out of pocket

Bariatric surgery is a major procedure, and your out-of-pocket cost depends on whether you have met your Part B deductible for the year. If you have not met it, you pay the full deductible amount first — in 2024 this is $240, though it changes yearly. After you meet the deductible, Medicare pays 80% of the approved surgical cost and you pay 20%.

The approved cost varies by region and by the type of surgery. Gastric bypass, gastric banding, and sleeve gastrectomy are all covered, but they have different approved amounts. Ask the bariatric surgery center to give you an estimate of what Medicare will approve for your specific surgery, so you know what your 20% share will be. The center can also tell you whether any of your visits before surgery (consultations, imaging, lab work) are covered separately or bundled into the surgical cost.

Medicare Advantage plan coverage

If you have a Medicare Advantage plan (Part C) instead of Original Medicare, your plan may cover bariatric surgery under different rules. Some Advantage plans require a lower BMI, or a shorter weight loss period, or different obesity-related conditions. A few plans do not cover bariatric surgery at all. You need to call your specific plan and ask what it requires.

When you call, have your plan member ID card ready and ask: "Does my plan cover bariatric surgery, and what documentation does my doctor need to submit?" The plan will tell you whether it uses Medicare's rules or its own, and what the approval process looks like. If your plan does not cover the surgery you need, you have the right to switch to Original Medicare during the annual open enrollment period (October 15 to December 7 each year).

What happens if Medicare denies your case

If Medicare reviews your case and decides you do not meet the requirements, the surgery center will tell you. The most common reasons for denial are: your BMI is below the threshold, you do not have a may have access to obesity-related condition, or your weight loss documentation does not show six months of medically supervised attempts. If you believe the denial is wrong — for example, if your doctor documented the weight loss visits but Medicare says it did not receive them — you can ask the surgery center to resubmit the case with clearer documentation.

You also have the right to appeal a Medicare denial. The bariatric surgery center can help you file an appeal, or you can contact Medicare directly at 1-800-MEDICARE. An appeal usually takes 30 to 60 days. If the appeal is denied, you can ask for a hearing before an administrative law judge, though this process takes longer.

Questions to ask your doctor before referral

Before your doctor refers you to a bariatric surgery center, ask these questions: "Do my BMI and health conditions meet Medicare's requirements?" "Have I completed six months of medically supervised weight loss?" "Which bariatric surgery center will you refer me to, and is it on Medicare's recognized list?" "What type of surgery do you recommend, and what is the typical recovery time?" "What are the risks and benefits of this surgery for my specific situation?"

Also ask: "Will Medicare likely cover this, or are there reasons it might deny my case?" If your doctor is unsure whether you meet the requirements, ask them to contact Medicare or the surgery center to confirm before the referral is made. This saves time and prevents a denial later.

Frequently Asked Questions

Does Medicare cover the visits before surgery, like consultations and lab work?

Yes. Your consultations with the bariatric surgery center, imaging (such as upper endoscopy), and lab work are covered as part of the surgical approval process. You pay your Part B deductible and then 20% of the approved cost for these visits, just as you would for any other Medicare-covered service. Ask the surgery center for an estimate of these costs upfront.

What if I have already had weight loss surgery that Medicare did not cover?

Medicare will not reimburse you for surgery that was done before you had Medicare coverage or before you met the requirements. If you had surgery as a Medicare beneficiary but it was denied, you may have been responsible for the full cost. Contact Medicare at 1-800-MEDICARE to ask whether your case can be reviewed.

Can I choose any bariatric surgeon, or does it have to be at a Medicare-recognized center?

Medicare only covers bariatric surgery performed at a recognized bariatric surgery center. Your doctor should refer you to a center on Medicare's list. If you prefer a surgeon who does not work at a recognized center, Medicare will not cover the surgery, and you will pay the full cost yourself.

How long does it take from referral to surgery?

The typical timeline is four to eight weeks from the time your doctor makes the referral to the time you have surgery. This includes the surgery center's review (one to two weeks), Medicare's review (one to three weeks), and scheduling (one to two weeks). Some centers are busier than others, so the timeline can vary.

If I have a Medicare Advantage plan, can I switch to Original Medicare to get bariatric surgery covered?

Yes, but only during the annual open enrollment period from October 15 to December 7. If your Advantage plan does not cover bariatric surgery and you want it covered, you can switch to Original Medicare during this window. The switch takes effect January 1 of the following year. Contact Medicare at 1-800-MEDICARE to make the change.