How to Get Insurance to Cover Knee Arthroscopy (and Appeal a Denial)

Written by Aptiva Health Editorial Team · Medically reviewed by Thomas Huhn, MD · Clinically reviewed by Simon Hoehn, DPT, PT · Reviewed by Crystal Brake, RCM Director and Taylor Sorrels, Esq. · Editorial & review standards · How we research

Knee arthroscopy is surgery done through a few small cuts with a tiny camera. It is often used to trim or repair a torn meniscus (the cushion inside the knee), remove loose pieces, or treat some cartilage and ligament problems.

Plans often review knee arthroscopy before they pay, especially when the knee also has arthritis. This guide explains what plans usually look for, how to get the request right, and what to do if it is denied. It is part of the Coverage & Appeals Center.

Why knee arthroscopy gets denied

Knee arthroscopy denials usually fall into one of these groups:

• Not medically necessary. The records didn’t show the plan’s criteria. See not medically necessary denials.
• No prior authorization, or approval for a different procedure or side. See missing prior authorization.
• Arthritis is the main problem. Many plans do not pay for arthroscopy to wash out or “clean up” a knee with arthritis.
• Physical therapy not tried or not documented. The plan wants proof that other treatment came first.
• Imaging missing. The plan wants an MRI or X-ray that matches your symptoms. See getting an MRI covered.
• A coding problem. The billed code doesn’t match what was approved. See coding error denials.

What plans usually look for

Each plan has its own written policy for knee surgery. Many plans also use a separate company to review surgery requests.

The criteria below are common examples, not rules for your plan. Ask your plan for its exact policy.

• Mechanical symptoms. For example, the knee locks, catches or gives way, not just pain.
• Imaging that shows the problem. For example, an MRI that shows a meniscus tear, or an X-ray that shows a loose piece.
• No more than mild arthritis. One payer’s policy, Aetna’s, limits many arthroscopy approvals to knees with no more than mild osteoarthritis (Aetna CPB 0673).
• Physical therapy and other care tried first. Aetna’s policy, as one example, asks for at least 6 weeks of formal, in-person physical therapy in the past year, confirmed by therapy notes or claims (Aetna CPB 0673). Other plans may ask for more, less or none.
• An exception for a locked knee. The same Aetna policy waives the therapy step when the knee is “locked” by a displaced bucket-handle meniscus tear (Aetna CPB 0673).
• A documented exam. Findings such as swelling, range of motion, joint-line tenderness or instability.

Medicare’s national rule for arthritic knees

Traditional Medicare has a national coverage rule for arthroscopy in knees with osteoarthritis. It does not cover arthroscopic lavage (washing out the joint) used alone, or debridement (cleaning up) when the only symptom is knee pain or when arthritis is severe (CMS: NCD 150.9). Other cases are left to the local Medicare contractor.

Guidelines your clinician may cite

The American Academy of Orthopaedic Surgeons (AAOS) 2021 knee osteoarthritis guideline says arthroscopy with lavage or debridement is not recommended when knee osteoarthritis is the main diagnosis. It also says partial meniscectomy “can be used” for meniscus tears in people with mild to moderate arthritis “who have failed physical therapy or other nonsurgical treatments” (AAOS knee OA guideline, 2021).

Medicare and the WISeR model

If you have Traditional Medicare, a model called WISeR began testing AI-assisted prior authorization in 2026, and it includes knee arthroscopy for knee osteoarthritis (CMS: WISeR Model). It runs in Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. Kentucky and Indiana are not part of it.

Medicare Advantage plans must follow the 2026 federal prior authorization timelines: 72 hours for urgent requests and 7 calendar days for standard requests (CMS: CMS-0057-F fact sheet).

What to ask your clinician to document

Before the request is sent, it helps if your chart clearly shows:

1. How and when the knee problem started, such as a twist or a fall.
2. Your symptoms, especially locking, catching or giving way.
3. Exam findings.
4. Imaging results and how they match your symptoms.
5. How much arthritis the X-ray shows.
6. Every treatment you have tried, such as physical therapy, medicine, a brace or an injection, for how long, and the result.
7. How the knee limits daily life, work or sports.

You can ask: “Does my chart show what my plan’s knee arthroscopy policy requires?” Bring a copy of the policy if you have it.

How to get knee arthroscopy covered

1. Ask whether prior authorization is needed. Call the plan or ask the surgeon’s office. Many plans require it for knee arthroscopy.
2. Get the plan’s knee surgery policy. Ask for the criteria for the exact procedure planned.
3. Make sure your chart matches it. Ask your surgeon to document symptoms, exam findings, imaging and prior treatment.
4. Send your therapy notes. If you did physical therapy somewhere else, make sure those notes reach the surgeon’s office.
5. Confirm the request was sent. Get the date and reference number.
6. Check the approval details. Match the approved procedure, side, facility and dates to what is scheduled.
7. If denied, appeal quickly. Ask for a peer-to-peer review and file an internal appeal with your surgeon’s letter.

Checklist before your surgery is scheduled

• Prior authorization approved, with a reference number
• Approved procedure and side match the surgery on your schedule
• Approved facility matches where the surgery will happen
• Surgery date falls inside the approved dates
• MRI or X-ray report is in your chart
• Physical therapy notes, including from other clinics, are in your chart
• You have a written cost estimate

What the approval should match

Sample appeal letter

You can fill in this letter by hand, or build one with the Appeal Letter Builder.

[Your name]
[Your address] · [Your phone] · [Your email]

[Date]

[Plan name or review company] — Appeals Department
[Address or fax from your denial letter]

RE: Appeal of knee arthroscopy denial
Member name: [Name] · Member ID: [Number]
Reference / case number: [Number]
Procedure: [e.g., right knee arthroscopy with partial medial meniscectomy]
Surgeon: [Name, credentials]
Date of denial: [Date]

To the Appeals Department:

I am appealing your denial of the surgery listed above. Your letter says: "[exact reason]."

I meet your criteria, [policy name or number]:
- Symptoms: [locking / catching / giving way, since when] — see [record, date].
- Exam findings: [findings] — see [record, date].
- Imaging: [MRI or X-ray, date] shows [finding] — see report.
- Arthritis: [X-ray grade or "no more than mild"] — see [report, date].
- Treatment tried first: [physical therapy, dates, number of visits, result; medicine; brace; injection] — see [records].

My surgeon's enclosed letter explains why the surgery is medically necessary and cites [guideline].

Enclosed:
- Letter of medical necessity from [surgeon]
- Visit notes and physical therapy records from [dates]
- MRI and X-ray reports from [dates]
- Your denial letter

Please approve the surgery. If you uphold the denial, please give me the specific reason, the criteria used, and the steps for external review in writing.

[If urgent:] My surgeon believes delay could harm my health. I request an expedited review.

Sincerely,
[Signature]
[Printed name]

Deadlines

Medicare has its own appeal steps (Medicare.gov: Original Medicare appeals; Medicare.gov: Medicare Advantage appeals).

To work out your own dates, try the Appeal Deadline Calculator. See Kentucky and Indiana for state steps. If your knee problem is urgent, ask for an expedited review.

What the process looks like

Here is how a knee arthroscopy request usually moves. Your plan may differ.

1. Your surgeon recommends arthroscopy and documents why.
2. The surgeon’s office sends the prior authorization request to your plan or its review company.
3. The plan reviews it against its knee surgery policy. Plans covered by the 2026 federal rule must decide within 7 calendar days, or 72 hours if urgent.
4. The plan approves, asks for more information, or denies. A request for more information is not a denial. Respond quickly.
5. If approved, you schedule surgery within the approved dates, at the approved facility.
6. If denied, your surgeon can ask for a peer-to-peer and you can file an appeal.

An example

*This is an illustrative example, not a real patient.*

Casey twisted a knee playing basketball. Since then, the knee catches and sometimes locks. An MRI shows a meniscus tear. The surgeon requests arthroscopy, and the plan denies it: “conservative treatment not documented.”

Casey had done six weeks of physical therapy at a clinic near work, but those notes never reached the surgeon. Casey asks the clinic to send them. The surgeon writes a letter that lists the locking, the MRI finding, the mild arthritis on X-ray and the therapy dates. Casey appeals with the letter and the notes.

The lesson: the plan wanted proof, and the proof was sitting in another clinic’s file.

Questions to ask before your surgery

• “Does my plan need prior authorization for this surgery?”
• “Who is sending the request, and when?”
• “Has it been approved? What is the reference number?”
• “Does the approval match the procedure, side and facility?”
• “Do you have my physical therapy notes from other clinics?”
• “What is my cost after insurance? Is there a cash-pay price?”

Common mistakes

• Scheduling before approval comes through. If the plan denies it later, you may owe the bill.
• Missing therapy notes, especially from another clinic.
• Approval for the wrong side or procedure.
• Not asking about a peer-to-peer. It can be faster than a written appeal.

If knee arthroscopy is denied

Read the denial letter closely. The Denial Decoder can help you understand the codes and wording.

Since January 1, 2026, Medicare Advantage, Medicaid, CHIP and HealthCare.gov Marketplace plans must give a specific reason when they deny a prior authorization request (CMS: CMS-0057-F fact sheet). A vague reason makes an appeal harder, so it is fair to ask for more detail.

Check that the letter tells you:

• The exact service that was denied and the date.
• The specific reason, in words you can act on.
• The policy or criteria the plan used. If it doesn’t, ask for a free copy (29 CFR 2560.503-1(g)(1)(v); 45 CFR 147.136(b)).
• Your deadline to appeal and how to send it.
• How to ask for an expedited review if it’s urgent.
• How to ask for an external review if the internal appeal fails.

If anything is missing, call the plan, ask for it in writing, and write down the date, the name of the person you spoke with, and a reference number.

Costs and your deductible while you wait

An appeal can take weeks. Meanwhile, it helps to understand what you might owe either way.

• If the appeal succeeds, the plan pays under your normal benefits. You still owe any deductible, copay or coinsurance.
• If you go ahead before a decision, you may owe the full bill if the appeal fails. Ask for a written cost estimate first.
• Check your EOB (explanation of benefits) when the claim is processed. It shows what was billed, allowed and owed.
• Ask about payment plans if a large bill arrives during the appeal. Ask the billing office to hold the account while the appeal is open.

A knee injury at work or in a car crash

If your injury happened at work, workers’ compensation usually pays, not your health plan. Workers’ comp has its own rules and appeal steps. See Kentucky workers’ comp and Indiana workers’ comp. If you were hurt in a car crash, your auto policy may pay first.

If coverage doesn’t work out

• Ask for an external review after a final internal denial.
• Ask about a cash-pay price, and get it in writing.
• Talk with your surgeon about other treatment while you appeal, such as physical therapy.

Before paying cash, ask how it affects your deductible. Cash payments may not count toward it unless your plan allows that.