Medicare Coverage for Hip and Knee Replacement Surgery

Hip and knee replacements are among the most common major surgeries performed on Americans 65 and older. More than 750,000 total joint replacements are done each year in the United States, and Medicare covers the vast majority of them. Understanding how Medicare pays for the procedure itself, the hospital stay, rehabilitation, and follow-up care can save you thousands of dollars and prevent unexpected bills.

Does Medicare Cover Joint Replacement Surgery?

Yes. Medicare covers medically necessary hip and knee replacement surgery. The coverage is split across Medicare Part A and Part B depending on how and where the surgery is classified.

The critical distinction — inpatient vs. outpatient — determines which part of Medicare pays and what your cost-sharing looks like.

Inpatient vs. Outpatient: The 2-Midnight Rule

Medicare uses the 2-midnight rule to determine whether a hospital patient is classified as inpatient (Part A) or outpatient under observation status (Part B).

Inpatient admission (Part A): If the physician expects your hospital stay to reasonably cross two midnights, the admission is classified as inpatient and billed under Part A. Most traditional joint replacement surgeries that require an overnight stay qualify here.

Outpatient/observation status (Part B): If your surgeon expects you to be discharged the same day or after one night, the hospital may classify you as outpatient under observation. In this case, the facility charges are billed under Part B, and you pay the Part B 20% coinsurance rather than the Part A deductible.

The distinction matters enormously for post-surgical rehab. Medicare will only cover skilled nursing facility (SNF) care after a joint replacement if you had a qualifying inpatient hospital stay of at least 3 consecutive days. A one-night observation stay does not count toward the 3-day requirement — which means no SNF coverage.

With the rise of same-day and next-day joint replacement programs, more surgeries are being performed on an outpatient basis. Ask your surgeon and hospital in advance how the admission will be classified.

What Part A Covers for Inpatient Joint Replacement

When your surgery is classified as inpatient, Part A covers:

Hospital stay: Part A pays for your semi-private room, nursing care, meals, operating room and anesthesia charges, and hospital services. Your cost is the Part A deductible — $1,676 per benefit period in 2025 — which covers days 1 through 60 of a hospital stay with no additional daily charges.

Post-acute rehabilitation in a skilled nursing facility: After a qualifying 3-day inpatient stay, Medicare Part A covers up to 100 days of SNF care if you need skilled nursing or therapy services. Days 1–20 have no patient coinsurance. Days 21–100 cost $209.50 per day in 2025. Day 101 and beyond are not covered.

The SNF coverage is not automatic. You must require skilled services — physical therapy, occupational therapy, or skilled nursing — not just custodial care. The SNF must be Medicare-certified and must accept your admission after the qualifying hospital stay.

Home health after SNF or directly after hospital discharge: If you are homebound after surgery, Medicare Part A (or Part B) covers medically necessary home health services, including physical therapy, occupational therapy, and skilled nursing visits. There is no patient coinsurance for home health.

What Part B Covers for Joint Replacement

Part B covers physician services at every stage of the surgical process:

• Pre-operative office visits: Your orthopedic surgeon’s evaluation, imaging (X-rays, MRI), and surgical planning
• Surgeon’s fee for the surgery itself: Part B pays 80% of the Medicare-approved amount after your Part B deductible ($257 in 2025); you pay 20%
• Anesthesiologist’s fee: Also covered under Part B at 80/20 cost-sharing
• Post-operative office visits: Follow-up appointments with your surgeon
• Physical and occupational therapy in an outpatient setting: Part B covers therapy after hospital discharge; the 20% coinsurance applies

The Cost of Joint Replacement: A Realistic Breakdown

For a traditional inpatient joint replacement, a beneficiary on Original Medicare (no supplement) can expect to pay:

Total out-of-pocket costs without supplemental coverage can reach $5,000–$10,000 for a patient who needs significant SNF rehabilitation.

How Medigap Eliminates Most Cost-Sharing

A Medigap Plan G policy eliminates virtually all of this cost-sharing. Plan G covers:

• The Part A hospital deductible ($1,676)
• All Part A coinsurance for hospital stays and SNF days 21–100
• The Part B 20% coinsurance for surgeon and anesthesiologist fees
• Outpatient therapy 20% coinsurance

After paying the Part B deductible ($257), a Plan G policyholder has zero out-of-pocket costs for the joint replacement surgery itself and for SNF days 21–100. On a surgery with $8,000 in total cost-sharing exposure, Plan G converts that to a $257 flat cost.

Medigap Plan N covers most of the same costs but requires a $20 copay per office visit and a $50 copay for emergency room visits that don’t result in inpatient admission. Plan N does not cover the Part B excess charges, though those are uncommon for inpatient surgery.

See Medigap Plans Compared: Which Supplement is Right for You? for a full breakdown of supplement options.

How Medicare Advantage Handles Joint Replacement

Medicare Advantage (MA) plans cover joint replacement surgery, but the financial experience is very different from Original Medicare + Medigap.

Network requirements: Most HMO plans require you to use in-network surgeons and facilities. If your preferred orthopedic surgeon or hospital is out of network, you may face significantly higher costs — or the plan may not cover the procedure at all outside of emergencies. PPO plans allow out-of-network care but at higher cost-sharing tiers (often 40–50% rather than 10–20%).

Prior authorization: Virtually all MA plans require prior authorization for elective joint replacement surgery. Your surgeon must document medical necessity and the plan must approve the procedure before surgery. Denials are not uncommon; you have appeal rights, but the process takes time.

Out-of-pocket maximums: MA plans cap your annual out-of-pocket costs, typically between $3,000 and $8,850 in 2025 (the federal cap). Once you reach this limit, the plan covers 100% of covered services for the rest of the year. This can be valuable if you have multiple major medical events in a year.

Post-acute care networks: MA plans often have preferred SNF networks. Using an out-of-network SNF may result in higher daily charges or no coverage at all. Always verify your post-surgical SNF options before surgery if you are on a Medicare Advantage plan.

For a direct financial comparison, see Medicare Supplement vs. Medicare Advantage: True Cost Comparison and Medicare Advantage vs. Original Medicare.

Outpatient Joint Replacement: A Growing Option

Advances in surgical technique and pain management have made same-day and 23-hour joint replacement surgery increasingly common. For healthy, motivated patients without significant comorbidities, outpatient surgery can mean faster recovery and greater convenience.

Under outpatient surgery:

• The facility fee is covered under Part B (80/20 cost-sharing) rather than Part A
• No 3-day inpatient stay requirement means SNF coverage is not triggered
• Home health remains available if you meet homebound and skilled care criteria
• Outpatient physical therapy under Part B covers your rehab sessions

Whether inpatient or outpatient surgery is appropriate for you depends on your health status, the complexity of your case, and your surgeon’s recommendation. The classification is a medical and administrative decision — not something you choose freely. However, understanding it lets you ask the right questions before surgery.

Pre-Authorization and Pre-Operative Requirements

Medicare itself does not require pre-authorization for joint replacement surgery — but many Medicare Advantage plans do. If you are on Original Medicare + Medigap, you simply need your surgeon to document medical necessity and order the procedure.

Common pre-operative requirements that affect Medicare billing:

Conservative treatment documentation: Medicare and most insurers want evidence that conservative treatments were tried before surgery. This typically means documented trials of physical therapy, anti-inflammatory medications, and steroid injections. The duration required varies but often 3–6 months of conservative management is expected for elective cases.

Medical clearance: Pre-operative cardiac and pulmonary evaluations are billed under Part B. Your primary care physician, cardiologist, and pulmonologist visit fees are covered at the standard Part B 80/20 split.

Pre-operative imaging: X-rays and MRI of the affected joint, required for surgical planning, are covered under Part B.

Bilateral Joint Replacement

Some patients need both hips or both knees replaced. Bilateral procedures can be performed either in a single operative session (staged bilateral same surgery day) or in two separate procedures.

Medicare covers bilateral joint replacement, but the cost-sharing can differ depending on whether procedures occur in the same hospital stay or separate admissions:

• Same admission: One Part A deductible covers both replacements; surgeon fees for each procedure are billed at reduced rates (the second procedure is typically reimbursed at 50% of the primary procedure rate)
• Separate admissions: Each admission triggers a new Part A deductible period if they occur more than 60 days apart — though Medigap Plan G eliminates this exposure

Talk with your surgeon about the medical and financial considerations of staging vs. simultaneous bilateral surgery.

Recovery and Long-Term Care Considerations

Joint replacement recovery typically takes 3–6 months for full functional recovery. Medicare covers the medically necessary portion of this:

• SNF care (inpatient, up to 100 days) when medically necessary skilled services are required
• Home health (no copay) when you are homebound and require skilled nursing or therapy
• Outpatient PT/OT under Part B (20% coinsurance) for ongoing rehabilitation

What Medicare does not cover is long-term custodial care — help with activities of daily living such as bathing, dressing, and mobility when no skilled services are required. If your recovery is prolonged or you have functional limitations, this can be a significant gap. Long-term care insurance can fill this gap if purchased before it is needed.

See Long-Term Care Insurance: What It Covers and When to Buy and Healthcare Costs in Retirement: What to Budget for planning context.

Financial Planning Before Surgery

A few steps to take before scheduling joint replacement surgery:

1. Verify your Medicare enrollment status: Confirm you are enrolled in Part A and Part B (or your MA plan) and that your coverage is current.
2. Check your Medigap or MA network: If you have Medigap, confirm the surgeon and facility accept Medicare assignment. If you have MA, confirm all providers are in network and that you understand your prior authorization requirements.
3. Clarify admission status in advance: Ask your surgeon and the hospital admissions department whether your surgery will be classified as inpatient or outpatient. If inpatient, confirm the expected length of stay.
4. Plan for SNF vs. home rehab: If you may need SNF care, identify Medicare-certified facilities near you and confirm they have availability. If home rehab is the plan, arrange for home health services and transportation to outpatient PT.
5. Understand your Part A benefit period: If you have had a previous hospitalization within the last 60 days, your current benefit period may still be active — meaning the Part A deductible may have already been met.

Joint replacement surgery is a major event, but with proper planning and the right supplemental coverage, the financial impact is manageable. Medigap Plan G policyholders in particular face minimal out-of-pocket costs, while Medicare Advantage beneficiaries face network and prior authorization considerations worth investigating before surgery is scheduled.