Medicare Prior Authorization Delaying Knee Surgery? What to Do

If your knee surgery is waiting on Medicare approval, first identify the exact operation and whether you have Original Medicare or Medicare Advantage. A federal program called WISeR can affect one narrow category of knee arthroscopy, but it does not apply to every knee operation or every Medicare beneficiary.

Does WISeR apply to your knee surgery?

Your procedure is likely within the WISeR model’s scope when all of these are true:

• You have Original Medicare, not Medicare Advantage.
• The service will be delivered in Arizona, New Jersey, Ohio, Oklahoma, Texas or Washington.
• The date of service is on or after January 15, 2026.
• The planned procedure is arthroscopic lavage or debridement for an osteoarthritic knee and uses a listed billing code. The July 2026 operational guide lists CPT code 29877.
• The claim comes from a setting covered by the model. For outpatient knee surgery, that will commonly be a hospital outpatient department or ambulatory surgery center.

The service location matters, not simply the state where you live. The model runs through December 31, 2031, according to the CMS WISeR frequently asked questions.

As of September 25, 2026, WISeR does not include total or partial knee replacement. It also does not include every meniscus, ligament or cartilage operation. CMS identifies the knee service as arthroscopic lavage and arthroscopic debridement for knee osteoarthritis. Inpatient-only and emergency services are excluded, and WISeR does not apply to Medicare Advantage members, according to the official CMS model overview.

Even when a service falls within WISeR, a provider may be exempt from review. Prior authorization is also technically voluntary, but a claim submitted without a prior-authorization decision is held for pre-payment medical review.

If a total knee replacement is delayed, asking only about “WISeR approval” may send you down the wrong path. The holdup could instead involve documentation, medical clearance, scheduling or a Medicare Advantage plan’s own authorization process.

How long should WISeR review take?

CMS says a WISeR participant will typically issue a decision within three calendar days of receiving an initial or resubmitted request. A qualifying expedited request should receive a decision within two days if waiting could seriously jeopardize the beneficiary’s life, health or ability to regain maximum function.

These are processing times after the WISeR participant receives the request—not a guarantee of the patient’s total waiting time. Routing a request through a Medicare Administrative Contractor (MAC), using mail or waiting for a Unique Tracking Number can add time. An approval, called a provisional affirmation, is valid for 120 days. A refusal, called a non-affirmation, must be reviewed by a human clinician with relevant expertise before it is issued. These rules appear in the CMS WISeR Provider and Supplier Operational Guide.

Reported performance has not always matched the target. The Electronic Frontier Foundation says records it obtained through litigation showed many early requests taking longer than 72 hours, including one that went unanswered for 83 days. It also reported 5,944 non-affirmations by two vendors during the program’s first three months and published provider accounts of patients waiting in pain. Those totals cover WISeR services generally; they do not show how many cases involved knee arthroscopy or whether each non-affirmation was incorrect. The EFF report also says turnaround figures cover the full request pathway, not only time controlled by a vendor.

What to ask the surgeon’s office today

The surgeon or facility handles the WISeR request. Ask:

1. What are the exact procedure name and billing code? Confirm whether this is knee replacement, arthroscopic debridement for osteoarthritis or another operation.
2. Is this being handled under WISeR? If you have Medicare Advantage, ask your plan for the authorization status and appeal rules instead.
3. Was a request submitted? Get the date, destination, submission method and confirmation number.
4. Has a Unique Tracking Number (UTN) been issued? A WISeR claim needs this number even if the decision was not affirmative.
5. Was the request affirmed, non-affirmed or dismissed? A dismissal may mean information was missing or invalid, the request was duplicated, or the service was outside WISeR. It is not a medical-necessity decision.
6. What information is missing? For osteoarthritis arthroscopy, CMS lists documentation of early or less-severe degenerative arthritis; symptoms beyond pain alone, such as catching or locking; and supporting records such as standing X-ray reports or MRI results. These are documentation rules for the clinician—not symptoms you should use to diagnose yourself.
7. Will the office resubmit and request peer-to-peer review? CMS allows unlimited complete resubmissions before a claim is denied. The requester may seek review with a clinician who has relevant specialty expertise.
8. Could expedited review be justified? The office must submit clinical documentation showing why waiting creates the required risk; pain alone does not automatically guarantee expedited handling.

Ask for copies of the request and decision notice, and keep a dated log of calls, reference numbers and cancelled surgery dates.

If the request was not affirmed

A WISeR non-affirmation is a preliminary coverage finding, not an appealable claim denial. The usual next step is for the provider to address the stated reason and resubmit the complete request.

The provider can perform the service and submit a claim after a non-affirmation, but CMS says that claim will be denied. If the non-affirmation found the service not medically reasonable and necessary and payment is expected to be denied, the provider should give you an Advance Beneficiary Notice of Non-Coverage (ABN) before performing it. Before agreeing to be financially responsible, ask why Medicare is expected not to pay, what the estimated cost is and what alternatives are available.

Formal appeal rights begin after Medicare issues a claim denial. Original Medicare has five appeal levels; the first is a redetermination requested by the deadline on the Medicare Summary Notice. Include why you believe the service should be covered and supporting material such as a doctor’s note. Follow the official Original Medicare appeal instructions or call 1-800-MEDICARE.

If pain, mobility or other symptoms are worsening while paperwork is pending, tell the surgical team. A clinical change may affect what care you need and should not be treated as only an administrative problem.