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Knee Replacement Explained
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All topics
  1. What it is
  2. Who it helps
  3. Timing
  4. The procedure
  5. Before and after surgery
  6. Recovery supplies
  7. Implant designs
  8. Side-by-side
  9. Robotics and alignment
  10. Robotic systems
  11. US manufacturers
  12. What the evidence says
  13. Value analysis
  14. Finding a surgeon
  15. Insurance and costs
  16. Questions to ask
  17. Resources
  18. Glossary
  19. References

For patients and families

Insurance and costs

Print your question sheet, preparation checklist and planning worksheets. Free, and nothing you type leaves your device.

Most people focus on the operation and only find out the cost when the bills arrive. They come from several places (the hospital, the surgeon, anesthesia, imaging, therapy), over months, and a revision or infection can multiply them. A revision can mean swapping one part or several, fixing instability or bone loss, or treating infection, and each of those changes the bill.

This page lays out realistic planning ranges for a first (primary) knee replacement and for a revision, explains how insurance turns those into what you owe, and walks through the steps that protect you. Your own plan and your surgical team's plan decide the final number, so use this to ask better questions and compare written estimates.

Download the full printable guide (PDF, 9 pages)

How to read the numbers

The ranges below are planning budgets, not national averages, fee schedules or quotes. They describe plausible totals across different hospitals and settings. Revision prices are especially uncertain, and real costs can be lower or much higher.

  • Allowed total is the negotiated price an in-network insurer and you pay together. It's usually far below the hospital's sticker price.
  • Your 20% share assumes an 80/20 plan where your deductible is already met and you haven't hit your yearly limit. Plans vary a lot; some use copays instead.
  • Self-pay is a negotiated cash estimate before any charity care, not the undiscounted sticker price.

Your out-of-pocket maximum caps what you pay in a plan year for covered, in-network care. Premiums, care your plan excludes, and most out-of-network charges usually don't count toward it.7

A worked example

Allowed total of $35,000. You still owe $2,000 of your deductible and have $7,000 left before your out-of-pocket maximum.

$2,000 + 20% of the remaining $33,000 = $8,600. Your yearly maximum caps that at $7,000.

First replacement, one knee, going home after surgery

Allowed totalYour 20% share*Self-pay
Surgeons$2,000–$5,000$400–$1,000$2,500–$6,000
Facility and implant$15,000–$35,000$3,000–$7,000$12,000–$35,000
Anesthesia$800–$2,000$160–$400$1,000–$2,500
Pre-op tests and imaging$300–$1,000$60–$200$300–$1,200
Outpatient rehab$1,000–$3,000$200–$600$1,000–$3,000
Total$19,100–$46,000$3,820–$9,200$16,800–$47,700

*Deductible already met, before your yearly out-of-pocket limit. Facility amounts include the implant. Excludes a long rehab stay and infection treatment.

In plain terms: the whole episode is often in the $19,100–$46,000 range before insurance. With a typical 80/20 plan, your share is usually capped by your out-of-pocket maximum, which for many plans is a few thousand to around ten thousand dollars a year.

Revision: one corrective operation, no infection

Allowed totalYour 20% share*Self-pay
Surgeons$3,000–$8,000$600–$1,600$3,500–$10,000
Facility and implant$25,000–$65,000$5,000–$13,000$22,000–$75,000
Anesthesia$1,200–$3,000$240–$600$1,200–$4,000
Workup and imaging$600–$2,000$120–$400$600–$2,500
Outpatient rehab$1,500–$6,000$300–$1,200$1,500–$6,000
Total$31,300–$84,000$6,260–$16,800$28,800–$97,500

*Same assumptions as above. This models a substantial component exchange, not a simple liner swap and not a full two-stage infection course.

A revision runs roughly $31,300–$84,000 before insurance, and staged infection treatment, fracture repair, major bone grafting or a long stay can push it higher. Nobody can honestly give you a single cash price for a two-stage infection treatment; get a written quote for each step.

What changes the bill

Approval for surgery isn't approval for everything. Check the surgeon and the exact facility, then anesthesia, imaging, equipment, therapy and home health. Approval for the operation doesn't automatically cover an inpatient stay, home IV antibiotics or a rehab facility.

Hospital or surgery center. A freestanding ambulatory surgery center (ASC) is for selected, healthier patients and is often cheaper. A hospital outpatient stay, overnight "observation" and a formal inpatient admission are three different things, billed differently, so a hospital quote isn't automatically an inpatient quote. Some revisions can be done as outpatient surgery, but infection, major bone loss, fracture or medical risk may need a hospital.2

Cash prices vary in what they include. One surgeon publishes self-pay knee replacement prices of $22,300 at a surgery center and $26,495 at a hospital, including the surgeon, anesthesia, facility and implant, with a one-night hospital stay if needed. Pre-op testing, prescriptions, equipment, travel and complications are not included.1 That's one example, not a national average, and it says nothing about revision prices. Ask whether physical therapy, medications, cold therapy devices and follow-up visits are included.

Infection changes everything. Treatment may be a washout that keeps the implant, a one-stage exchange, or two operations: removing the implant and placing a temporary antibiotic spacer, then putting in a new joint weeks or months later. Antibiotics and monitoring can run between the two. Ask for a separate estimate for each step and whether each needs its own approval.2 A price for a first replacement is not a price for an infected revision.

Costs people forget

  • Equipment. A walker or cane, a shower chair and toilet equipment, and optional cold therapy or compression devices. Ask whether a powered device is really needed, and whether it's rented, bought or covered. A basic set often runs about $100–$400.
  • Home and travel. Rides, parking, a hotel for a companion, meals, childcare and help with shopping add up, especially if your surgeon is far away. Everyday help around the house is different from skilled home health care and you may pay for it yourself.
  • Prescriptions. Check the cost of blood thinners and pain medication before surgery.
  • Revision extras. If there's infection, price the IV antibiotics, line, nursing, supplies, blood tests and infectious disease visits separately. Ask about braces, weight-bearing limits and bone graft before agreeing to any cash package.

Time off work

Lost income is often the biggest cost that never shows up on a bill. These are rough allowances for budgeting, not return-to-work rules. Get job-specific clearance from your team.

Type of workFirst replacementRevision
Flexible desk workOften 4–6 weeksOften 6–12+ weeks
Desk work with a commuteOften 6–8 weeksOften 8–12+ weeks
Standing or walking for long periodsOften 8–12 weeksOften 3–4+ months
Heavy labor, ladders, squattingOften 3–4 monthsOften 4–6+ months; some duties may stay off-limits

Knee recovery keeps improving for six to twelve months. With revision, bone healing, weight-bearing limits, infection and extra operations can stretch leave by months.23

Ask HR early about short-term disability, family and medical leave, a gradual return, and keeping your health insurance while you're out.

The traps

"Approved" doesn't mean paid. Prior authorization, whether a service is a covered benefit, whether each provider is in network, and your cost-sharing are four separate questions. A revision may need a new approval even if the first surgery was approved. A complication isn't automatically excluded just because the first surgery was planned.

Out-of-network doctors at an in-network hospital. Anesthesiologists, radiologists and assistant surgeons may bill separately. Under the No Surprises Act, most people with private insurance are protected from surprise out-of-network bills for this kind of care at an in-network hospital or surgery center, and you generally can't be asked to waive that protection for anesthesia. The law doesn't erase your deductible or coinsurance, and it generally doesn't cover ground ambulances, though some states do.8

A hospital bed isn't the same as being admitted. "Observation" is outpatient care, even overnight. Ask each day what your status is. Original Medicare generally requires three inpatient days before it covers a skilled nursing facility, and observation days don't count.910

"All-inclusive" rarely means everything. Bundles may leave out the implant, pre-op imaging, prescriptions, therapy or complications. A manufacturer's implant warranty isn't revision insurance; it may not pay the hospital, surgeon, anesthesia or rehab.

Watch the calendar

Two-stage treatment can straddle two plan years. With a $2,000 deductible and $7,000 maximum that reset each January, $40,000 of care in year one and $60,000 in year two could cost you $7,000 + $7,000 = $14,000. That's an example, not a prediction.

A cash price you pay outside insurance may not count toward your deductible or maximum, and a hospital's charity care may not cover independent doctors. Check both before paying.11

What insurers look for

First surgery. Insurers usually want X-rays showing advanced arthritis, pain or disability that limits daily life, exam findings, and a record of what you've tried first (medication, exercise or therapy, activity changes, a cane, injections) with dates and how it went. Medicare's local rules and private policies differ.45

Revision. The request should explain what failed: loosening, wear, instability, stiffness, fracture, bone loss or infection, backed by imaging and, when appropriate, blood tests and a joint fluid sample. Pain alone needs investigating; it doesn't prove a revision will help or be covered. You shouldn't have to repeat months of physical therapy before treatment for infection, fracture or a mechanical failure; ask for the policy that fits your actual problem.4

Code (CPT)What it usually means
27447Primary total knee replacement
27446Partial (one-compartment) knee replacement, not a total
27486Revision of one component
27487Revision of the femoral and entire tibial components

Descriptions are paraphrased. The billing office should confirm the exact codes, side and modifiers. A limited part swap isn't coded or priced like replacing everything.6

Before surgery: six steps

  1. Get one accurate description of the plan. The procedure and diagnosis codes, which side, the surgeon and facility, the proposed implant, expected inpatient or outpatient status, and the rehab plan. For a revision, what will be removed, kept or replaced, and whether it's one stage or two.
  2. Call your insurer with that information. Are these doctors and this exact location in my network? How much is left on my deductible and out-of-pocket maximum? What are the rules for surgery, therapy, equipment, home health and prescriptions? When does my plan year reset? Write down the reference number.
  3. Close any approval gaps. Get the authorization number, dates, codes and approved setting. Ask whether each revision stage, admission, home IV service and rehab stay needs its own approval. If denied, get the reason and policy in writing, ask your surgeon about a peer-to-peer review, and watch the appeal deadline.
  4. Get written estimates. With insurance, ask for an estimate based on your current benefits. Without insurance (or if you choose not to use it), you have a federal right to a Good Faith Estimate from each provider that bills you: the facility, surgeon and anesthesia group each send their own.12
  5. Clarify the bundle and deposit. Are implants, anesthesia, assistant surgeons, tests, an overnight stay, follow-up visits and rehab included? What happens if there's a complication, a cancellation or a transfer? What if the planned operation turns into a bigger one?
  6. Ask before going out of network. If no suitable in-network specialist is reasonably available, ask your insurer for a network-gap exception and a single-case agreement, in writing from both the insurer and the provider, stating you'll pay in-network cost-sharing and won't be balance billed.

Paying and disputing: five more

  1. Ask for help before taking on debt. Ask the hospital's financial counselor about charity care, hardship programs, uninsured discounts and payment plans, even if you're insured. Nonprofit hospitals must have a written financial assistance policy.11 Before using a credit card or medical financing, compare interest and deferred-interest terms.
  2. Price the discharge plan. Confirm the pharmacy, equipment supplier, therapy clinic and any home health or IV provider are in network and approved before you use them.
  3. Check your EOB against the itemized bill. An Explanation of Benefits isn't a bill. Match dates, procedures, side, network status, allowed amount and your share. Look for duplicates, denials and missing deposits. If something's wrong, ask for an itemized bill and a written hold on the disputed amount while it's reviewed.
  4. Use the right protection. For a surprise bill that may break the No Surprises Act, contact the provider and insurer first, then file at cms.gov/medical-bill-rights or call 1-800-985-3059.8 If you're self-pay and one provider bills you at least $400 more than its Good Faith Estimate, you may be able to dispute it within 120 days of the bill.13
  5. Keep everything in one place. Estimates, approvals, policy pages, assistance decisions, EOBs, receipts and call notes. Before paying a final balance, make sure insurance has finished processing and discounts and deposits are applied. For staged treatment, repeat this for each stage and each plan year.

Take this to your appointment

  • Which parts will be kept, swapped or removed, and is infection suspected?
  • What are my weight-bearing limits and how much help will I need, including between stages?
  • Write down: insurer reference number, authorization number, remaining deductible, remaining out-of-pocket maximum, written estimate, and plan-year reset date.

Download the full printable guide (PDF), with a fill-in worksheet.

This is general education, not a coverage decision or medical advice. Policies, prices and codes change; check them with your team and insurer before scheduling. See also finding the right surgeon.

Sources for this page

  1. Andrew Wickline, MD. Self-pay joint replacement (published example). andrewwicklinemd.com
  2. American Academy of Orthopaedic Surgeons, OrthoInfo. Revision total knee replacement. orthoinfo.org
  3. American Association of Hip and Knee Surgeons. Total knee replacement. hipkneeinfo.org
  4. Centers for Medicare & Medicaid Services. Local Coverage Determination: Total Joint Arthroplasty (L39911). cms.gov
  5. Aetna. Clinical Policy Bulletin 0660: Knee arthroplasty. aetna.com
  6. Centers for Medicare & Medicaid Services. Billing and Coding: Total Joint Arthroplasty (A59811). cms.gov
  7. HealthCare.gov. Out-of-pocket maximum/limit. healthcare.gov
  8. Centers for Medicare & Medicaid Services. Your rights when you have insurance (No Surprises Act). cms.gov
  9. Medicare.gov. Inpatient or outpatient hospital status. medicare.gov
  10. Medicare.gov. Skilled nursing facility care. medicare.gov
  11. Internal Revenue Service. Financial assistance policies (FAPs) for charitable hospitals. irs.gov
  12. Centers for Medicare & Medicaid Services. Your rights without insurance: Good Faith Estimates. cms.gov
  13. Centers for Medicare & Medicaid Services. Dispute a bill that's higher than your Good Faith Estimate. cms.gov