Medicare covers most surgeries, but not all of them, and the amount you pay depends on which part of Medicare you have and where the surgery happens

If you have Original Medicare (Part A and Part B), surgery in a hospital or outpatient surgery center is covered. Part A covers the facility, the operating room, and your hospital stay if needed. Part B covers the surgeon's fee and the anesthesiologist. If you have a Medicare Advantage plan (Part C), your coverage works differently — your plan decides what surgeries it covers and how much you pay, though it must cover at least what Original Medicare does.

The catch is that Medicare only covers surgeries it considers medically necessary. That means a doctor has to document that the surgery treats a condition, relieves pain, or restores function — not that it improves appearance or is elective. Cosmetic surgery, weight-loss surgery, and some joint replacements fall into gray areas where coverage depends on your specific diagnosis and the details of your case.

Key Takeaways

  • Original Medicare Part A covers the hospital facility and operating room; Part B covers the surgeon and anesthesiologist, and you pay a deductible plus coinsurance.
  • Medicare Advantage plans cover surgery differently depending on the plan, and you should call your plan before scheduling to confirm what you will owe.
  • Medicare only covers surgeries deemed medically necessary, so your doctor must document why the surgery is needed for your condition.
  • Outpatient surgery in a hospital or surgery center is usually cheaper than inpatient surgery because you avoid the hospital stay costs.
  • You can ask your surgeon's office to request a coverage information from Medicare before surgery so you know in advance what will be covered.

How Original Medicare Covers Surgery

With Original Medicare, Part A covers the operating room, facility fees, and any hospital stay before or after surgery. You pay a deductible for each hospital stay — the amount changes yearly, but as of 2024 it is $1,676 per benefit period. After you meet the deductible, you pay coinsurance (a percentage of the cost) for days 1 through 60 of your stay, and a higher coinsurance amount for days 61 through 90. If your surgery is outpatient — meaning you go home the same day — Part A still covers the facility, and you pay only the deductible.

Part B covers the surgeon's bill, the anesthesiologist, and any imaging or lab work done as part of the surgery. You pay 20 percent coinsurance after you meet your Part B deductible, which is $240 per year (as of 2024). If your surgeon is out-of-network, you may pay more. Many people buy Medigap coverage (supplemental insurance) to cover the deductible and coinsurance that Original Medicare leaves behind.

How Medicare Advantage Plans Cover Surgery

Medicare Advantage plans are run by private insurance companies and must cover at least what Original Medicare covers, but they set their own rules about how much you pay and which doctors you can see. Most plans require you to use in-network surgeons and facilities. Some plans cover surgery with a small copay; others use coinsurance like Original Medicare does. A few plans have no deductible for surgery, while others have a separate deductible just for surgery.

Before you schedule surgery, call your Medicare Advantage plan and ask: Does the plan cover this specific surgery? Which surgeons and facilities are in-network? What will I pay out of pocket? Some plans require prior authorization, meaning your doctor must get written approval from the plan before the surgery happens, or the plan may refuse to pay. If your plan denies coverage, you have the right to appeal.

What "Medically Necessary" Means for Surgery

Medicare will not pay for surgery unless a doctor documents that it is medically necessary — that it treats a disease, injury, or condition; relieves pain; or restores function. A facelift, tummy tuck, or breast augmentation for appearance alone is not covered. Cataract surgery is covered because it restores vision. Knee replacement is usually covered if arthritis is severe enough that conservative treatment has failed, but coverage can be denied if your doctor has not tried physical therapy first.

Weight-loss surgery is covered only if you have a BMI of 35 or higher and a weight-related condition like diabetes or heart disease, and only if your doctor has documented that you tried diet and exercise first. Bariatric surgery centers must be Medicare-approved. Some surgeries sit in the middle — your doctor may need to submit extra documentation to prove the surgery is necessary for your condition, not optional.

Getting a Coverage information Before Surgery

You do not have to wait until after surgery to find out whether Medicare will pay. Your surgeon's office can request an advance beneficiary notice (ABN) or a coverage information from Medicare before the surgery is scheduled. This is especially important if the surgery is unusual, if your condition is complex, or if you are worried Medicare might deny it.

If you have Original Medicare, your surgeon's office can contact Medicare directly to ask whether the surgery will be covered for your diagnosis. If you have Medicare Advantage, your plan must respond to a prior authorization request within 72 hours (or 24 hours for urgent cases). If Medicare or your plan says no, you can ask your doctor to appeal or to explain why the surgery is medically necessary for you. Getting this answer in writing before surgery protects you from surprise bills.

Outpatient Surgery vs. Inpatient Surgery Costs

Outpatient surgery — where you go home the same day — usually costs less than inpatient surgery because you avoid hospital room charges, meals, and nursing care for overnight stays. With Original Medicare, outpatient surgery means you pay only the Part A deductible plus Part B coinsurance. With inpatient surgery, you pay the Part A deductible plus coinsurance for each day you stay, which adds up quickly.

Your surgeon and the hospital decide whether your surgery can be done outpatient based on the type of surgery, your age, and your health. Some surgeries — like cataract removal or minor joint procedures — are almost always outpatient. Others — like major abdominal surgery or surgery on someone with serious heart disease — usually require a hospital stay. Ask your surgeon whether your surgery can be done outpatient and what the cost difference would be.

What to Do If Medicare Denies Coverage

If Medicare or your Medicare Advantage plan denies coverage for your surgery, you have the right to appeal. With Original Medicare, you can file an appeal with Medicare within 180 days of the denial. With Medicare Advantage, your plan must tell you how to appeal, and you usually have 60 days. You can ask your doctor to write a letter explaining why the surgery is medically necessary for you, and you can submit medical records that support the need.

Many denials are overturned on appeal, especially if your doctor provides new information or if the denial was based on incomplete records. You can also ask your doctor whether there is an alternative surgery or treatment that Medicare would cover, or whether waiting and trying other treatments first might change Medicare's decision later.

Frequently Asked Questions

Does Medicare cover surgery for arthritis or joint pain?

Joint replacement surgery is usually covered if arthritis is severe and conservative treatments like physical therapy, injections, or medication have not worked. Your doctor must document that you tried these other treatments first. Coverage varies by the specific joint and your diagnosis, so ask your surgeon to check with Medicare before scheduling.

Will Medicare pay for cataract surgery?

Yes. Cataract surgery is covered by Medicare when a cataract affects your vision enough that your doctor recommends removal. You pay the Part A deductible if it is done in a hospital outpatient center, plus Part B coinsurance for the surgeon. If you choose a premium lens implant instead of a standard one, Medicare covers only the standard lens and you pay the difference out of pocket.

What if my surgery is scheduled but I have not met my deductible yet?

You will owe the full deductible before Medicare starts paying its share. With Original Medicare, you can ask your surgeon's office to bill you for the deductible upfront, or you can pay it when you receive the bill after surgery. With Medicare Advantage, ask your plan how to pay the deductible — some plans let you pay it before surgery so there are no surprises.

Does Medicare cover emergency surgery?

Yes. Emergency surgery is covered the same way as planned surgery — Part A covers the facility, Part B covers the surgeon. You still owe the deductible and coinsurance. If you are out of the country when you need emergency surgery, Medicare will not pay, so travel insurance is important if you leave the United States.

Can I choose a surgeon outside Medicare's network?

With Original Medicare, you can see any surgeon who accepts Medicare, regardless of network. With Medicare Advantage, you usually must use in-network surgeons or pay much more. Check your plan's provider list before scheduling, or call your plan to ask whether your surgeon is in-network.