Original Medicare (parts A and B) and Medicare Advantage (Part C) cover medically necessary gastric bypass surgery. Part D may cover prescriptions you need for recovery, and Medigap can help lower out-of-pocket costs.

Gastric bypass, medically known as Roux-en-Y gastric bypass, is a type of bariatric surgery involving “bypassing” parts of the gastrointestinal tract to aid in weight loss.

According to the Centers for Medicare & Medicaid Services (CMS), open and laparoscopic gastric bypass surgery is covered by Medicare for beneficiaries who have:

  • a body mass index (BMI) of 35 or higher
  • at least one comorbid condition related to obesity, such as type 2 diabetes
  • previously tried medical treatment for obesity that did not work

It’s important to note that Medicare does not cover the cost of transportation to and from your surgical center.

Part A is inpatient hospital insurance. It covers any services you need during an inpatient hospital stay for gastric bypass surgery, including nursing care, doctors’ care, and medications.

Most people do not have to pay a monthly premium for Part A. In 2025, if you don’t meet the criteria for premium-free Part A, you’ll pay $285 or $518 each month.

Here are the other basic costs for an inpatient hospital stay in 2025:

  • $1,676 deductible for each benefit period
  • $0 copayment for days 1 to 60 of treatment after you pay your deductible
  • $419 copayment per day for days 61 to 90 of treatment
  • $838 coinsurance per day for days 91 to 150 of treatment while using your 60 lifetime reserve days
  • 100% of the treatment costs for days 151+

Part B is outpatient medical insurance. It covers any doctor and specialist visits you may need before and after your surgery.

It also covers laboratory tests, specific medications, and any durable medical equipment you may need during or after the procedure.

In 2025, most people will pay a monthly premium of $185. Your premium may be higher depending on your income.

After you pay a $257 deductible, you’ll generally pay 20% of all Medicare-approved costs for covered services while Medicare pays 80%.

Part C, or Medicare Advantage, must cover the same gastric bypass services as Original Medicare (parts A and B).

Private insurers administer Medicare Advantage plans, each setting its own costs and coverage limits. The premiums, deductibles, copayments, and coinsurance amounts you’ll pay depend on your chosen plan.

Staying in the plan’s network — that is, getting care from a list of approved healthcare professionals and facilities — usually costs less than going out of network.

Part D prescription drug plans cover take-home prescription medications. These plans can help pay for drugs that Original Medicare doesn’t cover. Most Medicare Advantage plans include Part D coverage.

After gastric bypass surgery, a healthcare professional may prescribe:

  • omeprazole capsules to help reduce your risk of peptic ulcers
  • ursodiol capsules or tablets to help reduce your risk of gallstones
  • octreotide injections to treat dumping syndrome

Each Part D plan sets its own cost and coverage amounts. The amount of coverage each plan provides depends on its formulary (drug list) and tier system.

Medigap is supplemental insurance that can help cover some of the out-of-pocket costs associated with Original Medicare.

This may include deductibles, coinsurance, and copayment amounts for your hospital stay, doctor’s visits, or even excess charges.

You cannot have a Medigap plan alongside Medicare Advantage.

If you plan to undergo gastric bypass surgery under Medicare, it’s important to understand what your plan will and will not cover.

You can call Medicare at 800-633-4227 (TTY: 877-486-2048) for help with your health insurance questions.

You can also contact your local State Health Insurance Assistance Program (SHIP) for additional assistance. To find a program near you, call the SHIP National Technical Assistance Center at 877-839-2675.