Medicare Advantage covers knee replacement, but the amount you pay depends on your specific plan and whether you use in-network doctors

Most Medicare Advantage plans do cover knee replacement surgery because it is considered medically necessary orthopedic care. However, Medicare Advantage is not one plan — it is a category of plans run by private insurance companies, and each plan sets its own rules about deductibles, copays, and which hospitals and surgeons are in-network. Before scheduling surgery, you need to check your own plan's documents to know what you will actually pay.

The basic coverage is there. The cost to you is what varies. A knee replacement at an in-network hospital might cost you a copay of $250 to $500 plus a portion of the surgeon's fee, while the same surgery out-of-network could cost thousands more. Some plans also require prior authorization — meaning the plan must approve the surgery before you have it, or they may refuse to pay.

Key Takeaways

  • Medicare Advantage plans cover knee replacement surgery, but you pay a copay or coinsurance amount that depends on your plan and whether you use in-network providers.
  • You must check your plan's Summary of Benefits and Coverage document or call your plan's member services line to learn your exact out-of-pocket cost before surgery.
  • Many Medicare Advantage plans require prior authorization from the insurance company before knee replacement, so your doctor's office must submit this request weeks in advance.
  • If your plan denies coverage or prior authorization, you have the right to appeal the decision, and your doctor can help you gather medical records to support the appeal.
  • Original Medicare (Part A and Part B) covers knee replacement with different cost-sharing rules, so comparing it to your Medicare Advantage plan may show you a better option.

How to find what your specific plan covers

Your Medicare Advantage plan mails you a Summary of Benefits and Coverage document each year, usually in September or October. This document lists what your plan pays for orthopedic surgery, what your copay or coinsurance is, and whether you must use in-network providers. If you cannot find it, log into your plan's website or call the member services number on the back of your insurance card.

When you call, ask these specific questions: Does the plan cover knee replacement? What is the copay or coinsurance for inpatient surgery? Do I need prior authorization? Which hospitals and orthopedic surgeons are in-network in my area? Write down the answers and the date you called, in case you need to reference them later.

If your doctor has already recommended knee replacement, ask your doctor's office to contact your plan directly. Many orthopedic offices have staff who specialize in verifying coverage and submitting prior authorization requests. This saves you time and reduces the chance of a surprise bill later.

Prior authorization and what happens if your plan says no

Prior authorization means your insurance company reviews your medical records and imaging (usually X-rays or an MRI) before approving the surgery. Your doctor's office submits this request, and the plan typically responds within 3 to 5 business days. If the plan approves it, you are cleared to schedule surgery. If the plan denies it, your doctor receives a letter explaining why.

Plans sometimes deny knee replacement if they believe the surgery is not yet medically necessary — for example, if your imaging shows mild arthritis but you have not tried physical therapy or injections first. If this happens, you have the right to appeal. Your doctor can write a letter explaining why surgery is necessary for your specific situation, and you can submit this with your appeal. The appeal process usually takes 30 days.

You can also ask your doctor to request an expedited (faster) appeal if you are in significant pain or your condition is worsening. Expedited appeals are decided within 72 hours.

In-network versus out-of-network costs

Medicare Advantage plans have networks of hospitals and doctors they contract with. If you use an in-network surgeon and hospital, your copay or coinsurance is lower and more predictable. If you use an out-of-network provider, you typically pay a much higher percentage of the cost, sometimes 40% to 50% of the total bill.

Before scheduling surgery, confirm that both your surgeon and the hospital where the surgery will take place are in-network. Ask your surgeon's office to verify this — do not assume a large hospital is in-network just because it is nearby. Some surgeons operate at multiple hospitals, and only some may be in-network for your plan.

If your preferred surgeon is out-of-network, you have options. You can ask your plan for a list of in-network orthopedic surgeons in your area, or you can ask your surgeon whether they can perform the surgery at an in-network hospital instead. Some surgeons will do this as a courtesy to their patients.

What happens after surgery: rehabilitation and follow-up care

Knee replacement does not end when you leave the hospital. Most people need physical therapy for 6 to 12 weeks after surgery, and your Medicare Advantage plan covers this if the therapist is in-network. Check your plan documents for the copay per physical therapy visit — it is often $20 to $50 per session.

Your surgeon will also schedule follow-up appointments at 2 weeks, 6 weeks, 3 months, and sometimes a year after surgery. These are covered under your plan's office visit copay, usually $20 to $40 per visit. If you need imaging (X-rays) during these visits, your plan may charge a separate copay for imaging, typically $10 to $50.

If you develop complications after surgery — such as infection, blood clots, or stiffness — additional hospital visits or procedures may be needed. These are covered by your plan, but you will pay your regular copays and coinsurance. Make sure you understand these costs before surgery so there are no surprises.

Comparing Medicare Advantage to Original Medicare for knee replacement

Original Medicare (Part A and Part B) also covers knee replacement, but the cost structure is different. With Original Medicare, you pay a hospital deductible (currently $1,676 per benefit period), then Medicare pays 80% of the surgeon's fee and hospital costs, and you pay 20%. You may also need a Medigap supplemental plan to cover that 20%, which costs extra each month.

With Medicare Advantage, you typically pay a fixed copay or coinsurance amount instead of a percentage. For example, you might pay $500 total for the hospital stay and surgeon, rather than 20% of a $15,000 bill. However, Medicare Advantage plans have annual out-of-pocket maximums (usually $5,000 to $7,000), meaning once you hit that limit, the plan pays 100% of covered services for the rest of the year.

If you are considering switching from Medicare Advantage to Original Medicare, or vice versa, you can only do so during the annual enrollment period (October 15 to December 7) or if you have a may have access to life event. If knee replacement is scheduled soon and you are unhappy with your current plan's coverage, you may not be able to switch before surgery.

Questions to ask your doctor and your insurance plan

Before scheduling knee replacement, write down these questions and get answers in writing:

  • Does my Medicare Advantage plan cover knee replacement surgery?
  • What is my copay or coinsurance for the hospital stay and surgeon's fee?
  • Do I need prior authorization, and if so, how long does it take?
  • Which hospitals and surgeons in my area are in-network for my plan?
  • What is my annual out-of-pocket maximum, and how much have I already spent this year?
  • Does my plan cover physical therapy after surgery, and what is the copay per visit?
  • If my plan denies coverage, what is the appeal process and how long does it take?

Frequently Asked Questions

Can I have knee replacement surgery if my Medicare Advantage plan requires prior authorization and I am in pain right now?

Yes. Prior authorization does not delay your surgery — it is a paperwork step your doctor's office handles before you schedule. Your doctor can request expedited authorization if you are in severe pain, which is decided within 72 hours. You can schedule surgery as soon as authorization is approved, which is usually within 3 to 5 business days.

What if I have already had knee replacement and my plan is now refusing to pay?

Contact your plan's member services line when ready and ask why the claim was denied. Common reasons include billing errors, use of an out-of-network provider, or a missing prior authorization. You have the right to appeal any denial. Ask your surgeon's office to help — they often know how to resolve billing disputes with insurance companies.

Does Medicare Advantage cover a second knee replacement if I need both knees done?

Yes, but most surgeons recommend spacing the surgeries 3 to 6 months apart so you can recover and regain strength between procedures. Your plan covers both surgeries the same way it covers the first one — with the same copay or coinsurance. However, you will meet your annual out-of-pocket maximum twice if both surgeries happen in the same calendar year.

If I switch Medicare Advantage plans during open enrollment, will the new plan cover my knee replacement that is already scheduled?

It depends on when your surgery is scheduled and when your new plan starts. If your surgery is scheduled before your new plan's coverage begins, your old plan pays. If it is scheduled after your new plan starts, the new plan pays. Call both plans to confirm which one will cover your surgery, and make sure your surgeon's office has the correct insurance information.

What if my doctor says I need knee replacement but my Medicare Advantage plan says it is not medically necessary yet?

You can appeal the plan's decision. Ask your doctor to write a letter explaining why surgery is necessary for your specific situation — for example, if you have severe pain that limits your daily activities or if you have already tried and failed other treatments. Submit this letter with your appeal. If the plan denies the appeal, you can request an independent review through Medicare.