Does Medicare cover knee replacement surgery? Yes — Medicare provides substantial coverage for knee replacement when it is medically necessary. Total and partial knee replacement surgeries are among the most common major procedures performed on Medicare beneficiaries, and understanding the coverage details, costs, and recovery expectations can help you plan effectively.
According to the Agency for Healthcare Research and Quality (AHRQ), over 700,000 knee replacements are performed annually in the United States, with the majority of patients being over 65. As the population ages, this number continues to grow. Medicare’s coverage ensures that beneficiaries with debilitating knee pain and arthritis can access this life-changing procedure. For a comprehensive look at expenses, see our guide on knee replacement surgery cost.
What Medicare Covers for Knee Replacement
Medicare coverage for knee replacement surgery spans multiple parts of the program:
Medicare Part A (Hospital Insurance):
- Inpatient hospital stay for the surgery
- Semi-private room and board
- Nursing care during the hospital stay
- Meals and medications administered during hospitalization
- Operating room and recovery room costs
- The prosthetic knee implant itself
Medicare Part B (Medical Insurance):
- Surgeon’s fees for the procedure
- Anesthesia services
- Pre-operative consultations and medical clearance
- Diagnostic imaging (X-rays, MRIs) needed to plan surgery
- Post-operative follow-up visits with the surgeon
- Outpatient physical therapy and rehabilitation
- Durable medical equipment (DME) such as a walker, crutches, or knee brace
Medicare Part A (Skilled Nursing Facility):
- If you need inpatient rehabilitation after surgery, Medicare Part A may cover a skilled nursing facility (SNF) stay for up to 100 days following a qualifying hospital stay of three or more days.
Out-of-Pocket Costs for Knee Replacement
While Medicare covers knee replacement, beneficiaries are responsible for standard cost-sharing:
- Part A deductible: $1,676 per benefit period (2026), covering the first 60 days of an inpatient hospital stay.
- Hospital coinsurance: $0 per day for days 1-60. If the stay exceeds 60 days, coinsurance of $419 per day applies for days 61-90.
- Part B costs: After the annual Part B deductible ($257 in 2026), you pay 20% of the Medicare-approved amount for surgeon fees, anesthesia, outpatient therapy, and DME.
- SNF coinsurance: Days 1-20 in a skilled nursing facility have $0 coinsurance. Days 21-100 require coinsurance of $209.50 per day (2026).
The total cost of knee replacement surgery (hospital, surgeon, anesthesia, implant, rehabilitation) can range from $30,000 to $60,000 or more depending on the facility, geographic location, and complexity. Your out-of-pocket share under Original Medicare — after the Part A deductible and Part B coinsurance — could range from $2,000 to $8,000 or more without supplemental coverage.
Medigap plans can significantly reduce these costs. For example, a Plan G Medigap policy covers the Part A deductible, hospital coinsurance, and the 20% Part B coinsurance, leaving you responsible only for the Part B deductible.
Inpatient vs. Outpatient Knee Replacement
An important consideration for Medicare coverage is whether your knee replacement is classified as inpatient or outpatient:
- Inpatient: You are formally admitted to the hospital. Coverage falls under Part A with the Part A deductible and inpatient cost-sharing rules. Most traditional knee replacements are performed on an inpatient basis.
- Outpatient: Some knee replacements, particularly partial knee replacements and procedures on healthier patients, are now performed on an outpatient basis at hospitals or ambulatory surgery centers. Outpatient procedures are covered under Part B, with the 20% coinsurance applying to all services.
CMS removed total knee replacement from the Inpatient-Only (IPO) list in 2020, meaning hospitals and surgeons can now perform the procedure on an outpatient basis when appropriate. This shift can affect your cost-sharing, SNF eligibility, and recovery planning.
If your knee replacement is performed as outpatient, you may not meet the three-day inpatient stay requirement for Medicare-covered skilled nursing facility care. Discuss the classification with your surgeon and hospital before the procedure to understand the financial implications.
Prior Authorization and Medical Necessity
For Original Medicare, knee replacement surgery generally does not require prior authorization — your doctor determines medical necessity. However, some Medicare Advantage plans do require prior authorization for major surgeries including knee replacement.
To qualify as medically necessary, your condition typically must include:
- Significant knee pain and functional limitation from osteoarthritis, rheumatoid arthritis, or post-traumatic arthritis
- Failure of conservative treatments such as physical therapy, medications, injections, and activity modification
- Radiographic evidence of substantial joint damage
- Impact on daily activities and quality of life
Your orthopedic surgeon will document the medical necessity based on your symptoms, imaging, and treatment history.
Recovery and Rehabilitation Coverage
Medicare covers rehabilitation services that are essential to recovery from knee replacement:
- Inpatient rehabilitation: If you qualify, Medicare Part A covers inpatient rehabilitation at a hospital or skilled nursing facility. You must meet specific criteria, including the ability to participate in intensive therapy (typically three hours per day, five days per week for inpatient rehab facilities).
- Outpatient physical therapy: Medicare Part B covers outpatient physical therapy to restore mobility, strength, and function. You pay 20% coinsurance after the Part B deductible.
- Home health services: If you are homebound after surgery, Medicare covers home health services including physical therapy, occupational therapy, and skilled nursing visits at no cost to you (no deductible or coinsurance for home health).
A typical recovery timeline includes:
- Hospital stay of one to three days (or same-day discharge for outpatient cases)
- Use of a walker or crutches for two to four weeks
- Physical therapy for six to twelve weeks
- Return to most daily activities within six to eight weeks
- Full recovery and maximum improvement within three to six months
Choosing a Surgeon and Facility
Your choice of surgeon and facility can significantly affect both outcomes and costs:
- Medicare-participating providers: Choose a surgeon and facility that accept Medicare assignment to avoid excess charges.
- Hospital quality ratings: CMS publishes hospital quality ratings, including complication rates for joint replacement, at Medicare.gov’s Care Compare tool.
- Comprehensive Care for Joint Replacement (CJR): Some hospitals participate in Medicare’s bundled payment program for joint replacement, which can incentivize higher quality and lower costs.
- Surgeon volume: Research consistently shows that surgeons who perform more knee replacements tend to have better outcomes and fewer complications.
For more context on Medicare coverage policies and how they affect major procedures, visit our healthcare policy guide.
Frequently Asked Questions
Does Medicare cover both knees at the same time?
Medicare can cover bilateral (both knees) knee replacement in a single surgery when medically necessary. However, most orthopedic surgeons recommend staging the procedures several weeks or months apart to allow for recovery and reduce surgical risk. Bilateral same-day surgery is typically reserved for carefully selected patients. Coverage applies the same way regardless of whether one or both knees are done.
How long is the hospital stay for knee replacement with Medicare?
Hospital stays for knee replacement have decreased significantly in recent years. Most inpatient total knee replacements involve a one- to three-day hospital stay. Partial knee replacements and outpatient total knee replacements may involve same-day discharge or a one-night stay. The shift toward shorter stays is driven by advances in surgical techniques, pain management, and rehabilitation protocols.
Does Medicare cover robotic knee replacement?
Medicare covers the knee replacement procedure regardless of whether the surgeon uses traditional or robotic-assisted techniques. The surgeon’s fee and facility fee are covered the same way. However, some hospitals may charge higher facility fees for robotic surgery, and these costs are generally absorbed by the facility under Medicare’s payment structure, not passed on to the patient.
Can Medicare deny knee replacement surgery?
Medicare rarely denies knee replacement surgery when properly documented medical necessity exists. However, denials can occur if documentation is insufficient, if conservative treatments have not been adequately tried, or if the procedure is classified incorrectly. Medicare Advantage plans may deny prior authorization requests, which can be appealed. If denied, you have the right to appeal the decision.
What if I need knee replacement but cannot afford the out-of-pocket costs?
Several options exist: Medigap plans can cover most or all of your cost-sharing; Medicare Advantage plans may have lower out-of-pocket costs for surgery; Medicare Savings Programs can help with premiums and cost-sharing for qualifying low-income beneficiaries; and many hospitals offer financial assistance or payment plans for patients who qualify.
Practical Takeaway
Medicare does cover knee replacement surgery, including the hospital stay, surgical fees, implant, rehabilitation, and follow-up care. Your out-of-pocket costs depend on whether you have Original Medicare with or without a Medigap plan, or a Medicare Advantage plan. Before scheduling surgery, confirm your procedure’s inpatient or outpatient classification, understand the cost-sharing implications, check whether your MA plan requires prior authorization, and research your surgeon and facility using Medicare’s quality tools. With proper planning, knee replacement on Medicare can be a manageable and life-improving experience.