Medicare Advantage Denials in Orthopaedics: What the First Public Data Shows and How to Fight Back in 2026

Medicare Advantage denials hit orthopaedic practices harder than most specialties because orthopaedics depends on the services MA plans review most: joint replacement, spine surgery, advanced imaging, injections, and post-operative therapy. The first public payer data, released in 2026 under a CMS transparency rule, shows Medicare Advantage plans denied 12% of standard prior authorization requests in 2025, and that 67% of the denials that were appealed were overturned.

The practical takeaway for an orthopaedic group is that most MA denials are not final. Practices that know the rules MA plans must follow, document to Traditional Medicare coverage criteria, and appeal systematically recover revenue that others write off.

This guide covers what the new data shows, the federal rules that bind Medicare Advantage plans, where orthopaedic claims get denied, and a step-by-step playbook to prevent and overturn MA denials.

Why Medicare Advantage Denials Matter More Every Year

More than half of eligible Medicare beneficiaries are now enrolled in Medicare Advantage, according to KFF. For many orthopaedic groups, MA patients represent a large and growing share of joint replacement and spine volume, because the patients who need those procedures skew older.

Unlike Traditional Medicare, which rarely requires prior authorization for orthopaedic surgery, MA plans use prior authorization, concurrent review, and post-payment audits extensively. Every one of those touchpoints is a chance for a denial, a delay, or a downcode.

The Office of Inspector General has flagged the problem repeatedly. A 2022 OIG report (OEI-09-18-00260) found that 13% of MA prior authorization denials it reviewed were for services that met Medicare coverage rules and likely would have been approved under Traditional Medicare. In June 2026, two new OIG reports found that when patients appealed MA denials of skilled nursing facility admissions, plans reversed 95% of them. Those reports focused on post-acute care, which matters directly to orthopaedic surgeons discharging joint replacement patients.

What the First Public Prior Authorization Data Shows

Under the CMS Interoperability and Prior Authorization Final Rule (CMS-0057-F), Medicare Advantage, Medicaid, and ACA Marketplace plans had to publish their 2025 prior authorization metrics by March 31, 2026. KFF analyzed the data from plans covering about 25 million MA enrollees and published the results on August 13, 2026.

The key findings for Medicare Advantage:

• 12% of standard prior authorization requests were denied, and 10% of expedited requests were denied.
• 67% of denials that were appealed were overturned.
• Median decision time was about one day for standard requests.

Two conclusions follow. First, the overturn rate means a large share of initial MA denials do not hold up when someone pushes back with the right documentation. Second, the fast median decision time means the bottleneck is usually not the payer. It is the practice's ability to submit complete requests and to appeal quickly when a denial comes back.

The Rules Medicare Advantage Plans Must Follow

Many practices treat MA plans like commercial plans with their own coverage rules. That is a mistake. Federal rules limit how MA plans can deny care, and orthopaedic groups should cite them.

The CY2024 Medicare Advantage final rule (CMS-4201-F), effective January 1, 2024, requires that:

• MA plans follow Traditional Medicare coverage criteria. Plans must comply with National Coverage Determinations, Local Coverage Determinations, and general Medicare coverage and benefit conditions. They may use internal criteria only when Medicare criteria are not fully established, and those criteria must be publicly available and based on current evidence.
• Prior authorization is limited in purpose. It may be used only to confirm the presence of diagnoses or other medical criteria and to ensure the service is medically necessary under those standards.
• Approvals last for the course of treatment. An approved prior authorization must remain valid for as long as medically necessary to avoid disruptions in care.
• New enrollees get a transition period. Plans must provide a minimum 90-day transition period for active courses of treatment when an enrollee switches into a new MA plan.
• Medical necessity denials require qualified reviewers. A denial based on medical necessity must be reviewed by a physician or other appropriate health care professional with expertise in the relevant field.
• The two-midnight rule applies. MA plans must follow Traditional Medicare's rules for inpatient admissions, which matters for joint replacement patients whose clinical condition supports an inpatient stay.

CMS also clarified in a February 2024 FAQ that MA plans may use algorithms and AI tools to assist coverage decisions, but a decision must be based on the individual patient's circumstances, not solely on an algorithm or broad data set.

When an MA denial conflicts with an NCD, LCD, or Traditional Medicare's coverage standards, say so explicitly in the appeal and cite the rule.

Where Orthopaedic Claims Get Denied by Medicare Advantage Plans

In our work with orthopaedic groups, MA denials cluster in a predictable set of areas.

Joint replacement: medical necessity and site of care

Total knee and total hip arthroplasty requests are denied when documentation does not show failed conservative treatment, functional limitation, and radiographic severity. Site-of-care denials, where the plan approves the procedure only in an outpatient or ASC setting, are also common. The two-midnight rule gives surgeons a basis to push back when the patient's comorbidities support inpatient admission.

Spine surgery and injections

Lumbar fusion, cervical fusion, and epidural steroid injections are heavily reviewed. Denials usually cite insufficient conservative care, imaging that does not correlate with symptoms, or frequency limits on injections. Many LCDs spell out the documentation required, which makes them valuable in appeals.

Advanced imaging

MRI and CT orders are frequently reviewed by radiology benefit managers on behalf of MA plans. Missing clinical history and incomplete physical exam findings are the typical cause.

Post-operative therapy and post-acute care

MA plans limit physical therapy visits and deny or shorten skilled nursing and inpatient rehabilitation stays. The OIG's June 2026 findings on skilled nursing denials are directly relevant to joint replacement discharge planning.

Coding and payment denials

Beyond prior authorization, MA plans deny or downcode claims for modifier errors (especially 25, 59, and global period modifiers), bundling, and E&M level. These denials are coding problems, and they are the most preventable.

A Playbook to Prevent Medicare Advantage Denials

1. Know which services each MA plan reviews

Build and maintain a list of services requiring prior authorization for each MA plan you see most. Plans publish these lists and update them, often each January. Because Medicare's annual enrollment period runs October 15 through December 7, re-verify every January surgical patient's plan before surgery.

2. Document to Traditional Medicare criteria

Because MA plans must follow NCDs and LCDs, the strongest prior authorization request quotes the applicable criteria and shows where the chart meets each one. For joint replacement, that means duration and type of conservative treatment, radiographic findings, functional limitation, and the effect on daily activities.

3. Submit complete requests the first time

Incomplete requests lead to pended cases and denials. A standard packet for your top procedures, including the office note, imaging report, conservative treatment history, and a short letter of medical necessity, cuts back-and-forth.

4. Match the authorization to the claim

A common and fully avoidable MA denial is a mismatch between the authorized CPT code and the billed CPT code. It happens when a surgeon performs an additional or different procedure intraoperatively. Reconcile authorizations against op notes before the claim is submitted, and request retro-authorization when the plan allows it.

5. Code cleanly

MA plans apply NCCI edits and modifier rules aggressively. Accurate CPT, ICD-10, and modifier selection, supported by the op note, removes a whole category of denials.

A Playbook to Overturn Medicare Advantage Denials

When a denial comes back, speed and structure matter.

Read the denial reason. Since January 1, 2026, CMS-0057-F requires plans to give a specific reason for prior authorization denials. The reason tells you exactly what to fix.

Request a peer-to-peer. For medical necessity denials, a surgeon-to-physician conversation often resolves the issue fastest. Prepare the surgeon with a one-page summary of the relevant criteria and chart evidence.

File a reconsideration. Pre-service reconsiderations are generally decided within 30 calendar days for standard requests and 72 hours for expedited requests. Payment reconsiderations generally allow 60 days. If the plan upholds its denial, it must automatically forward the case to the Independent Review Entity. Note that contracted providers may be bound by contract dispute terms for payment disputes, so check your MA contracts.

Cite the rules. Reference the applicable NCD or LCD, CMS-4201-F's requirement that plans follow Traditional Medicare coverage criteria, and any evidence the plan used internal criteria that are not publicly available.

Track every outcome. Log denial reason, plan, CPT code, and appeal result. Within a few months, you will see which plans and services generate most of your MA write-offs, and that data belongs in your next contract negotiation.

How Automation Helps Orthopaedic Practices With Medicare Advantage Denials

MA denials combine three kinds of work that automation handles well: getting coding right before submission, reconciling authorizations to what was performed, and drafting appeals with the right documentation attached.

Maia's AutoCoder recommends CPT, ICD-10, and modifier selections with clinical justification inside the EHR before a human coder reviews the chart. Maia's Prior Auth Reconciliation identifies mismatches between authorized and performed procedures and supports timely retro-authorizations. Maia's Denial Appeals generates payer-specific appeal letters that cite the documentation and coverage criteria. Orthopaedic groups use Maia across Athena, eClinicalWorks, and coming soon, Epic, ModMed, NextGen, and Tebra.

Frequently Asked Questions

What percentage of Medicare Advantage prior authorization requests are denied?

According to KFF's August 2026 analysis of 2025 payer-reported data, Medicare Advantage plans denied 12% of standard prior authorization requests and 10% of expedited requests. Rates vary widely by plan.

How often are Medicare Advantage denials overturned on appeal?

KFF found that 67% of Medicare Advantage prior authorization denials that were appealed in 2025 were overturned. The OIG reported in June 2026 that MA plans reversed 95% of appealed skilled nursing facility admission denials.

Do Medicare Advantage plans have to follow Medicare coverage rules?

Yes. Under CMS-4201-F, effective January 1, 2024, MA plans must follow National Coverage Determinations, Local Coverage Determinations, and general Traditional Medicare coverage rules. They may use internal criteria only when Medicare criteria are not fully established, and those criteria must be publicly available and evidence based.

Does the two-midnight rule apply to Medicare Advantage joint replacement patients?

Yes. Since January 1, 2024, MA plans must follow Traditional Medicare's inpatient admission rules, including the two-midnight rule. Surgeons can use it to support inpatient admission when the patient's clinical condition justifies it.

Can Medicare Advantage plans use AI to deny claims?

MA plans may use algorithms and AI tools to assist coverage decisions, but CMS guidance issued in February 2024 states that decisions must be based on the individual patient's circumstances and not solely on an algorithm. Medical necessity denials must be reviewed by an appropriately qualified clinician.

What is the fastest way to reduce Medicare Advantage denials in an orthopaedic practice?

Start with the preventable denials: reconcile authorizations to the procedures performed, code modifiers correctly, and submit complete prior authorization packets that document to Medicare coverage criteria. Then appeal consistently, because most appealed MA denials are overturned.

See how Maia handles this automatically for orthopaedic practices. Book a demo at usemaia.com.