Medicare Advantage Prior Authorization Denials: What the OIG Report Found

A 2022 HHS Office of Inspector General (OIG) report found that Medicare Advantage plans overturned 75% of their own prior authorization denials during the study period (2019–2020). Yet only 18% of denied requests were ever appealed by beneficiaries or their providers. That means millions of medically necessary services, drugs, or procedures were never reconsidered—even though, when challenged, three out of four denials were reversed. The report analyzed 39,000 denied prior authorization requests across the 15 largest Medicare Advantage organizations, representing over 60% of beneficiaries enrolled in Part C plans.

Applicability boundary: The 75% overturn rate applies to internal plan appeals (Level 1) and reflects the experience of the 15 largest MA organizations during 2019–2020. Smaller plans, employer group waiver plans, or plans with different utilization review contractors may show different rates. Also, the study excluded services denied because they were not Medicare-covered benefits (e.g., routine dental, cosmetic surgery) or because the beneficiary was not enrolled in a plan that covers that category. If your denial is for a service Medicare explicitly excludes from coverage, an appeal won’t overturn it—the plan has no authority to pay for non-covered benefits.

One Failure Mode: Low Appeal Rates Due to Lack of Provider Engagement

The single biggest reason beneficiaries miss the chance to overturn a denial is that neither the patient nor the ordering provider files an appeal. The OIG report shows that in cases where a provider did file an appeal on behalf of the patient, the overturn rate was even higher—nearly 82%. But many providers skip the internal plan appeal (Level 1) because they assume it’s futile, or they lack the staffing to deal with the administrative burden.

How to Detect This Early

• Red flag: Your provider says “the plan denied it, try a different drug” without first offering to file a standard appeal. This is a signal the provider may not be aware of the high overturn rate or is choosing not to engage.
• What to look for: When you receive a Notice of Denial from your Medicare Advantage plan, check the “Appeal Rights” section. If it lists a deadline (usually 60 days from denial), make sure someone (you or your doctor) files the appeal within that window. Most denials are not final; they are coverage decisions that can be challenged.

How to Overturn a Denied Prior Authorization

If your Medicare Advantage plan denies a prior authorization for a service, drug, or item, use this process. The OIG data confirms that following through increases your chances of getting coverage.

Step 1: Confirm the Denial Type and Deadline

• Identify the document: You should receive a written Notice of Denial (also called an Integrated Denial Notice or Coverage Determination Notice). It will state the reason (e.g., not medically necessary, experimental, out-of-network).
• Check the appeal window: You typically have 60 calendar days from the date of the denial notice to file a standard appeal. Some plans allow up to 90 days, so read the notice carefully.
• Verify your plan’s process: Go to your plan’s member portal or call the number on your ID card. Ask for the exact appeal form and confirm the deadline. Many plans also list appeal instructions in your Evidence of Coverage (EOC) document. Do not rely on the provider’s word alone—confirm the deadline yourself.
• Likely cause of missed opportunity: Many beneficiaries toss the notice or assume it’s a final decision. The OIG report found that less than 1 in 5 denials get appealed—this is the primary failure point.

Step 2: File a Level 1 (Plan-Level) Appeal

• Who can file: You, your authorized representative, or your provider. The fastest path is to have your provider submit the appeal because they can include clinical notes and medical necessity documentation.
• What to include: A written statement explaining why the denial is wrong, plus supporting medical records (lab results, imaging reports, doctor’s note). Use the plan’s appeal form (available on the plan’s website or by calling the number on your ID card).
• Timeframe for a decision: The plan must respond within 7 calendar days for standard appeals, but can request a 14-day extension. For expedited (urgent) appeals, the plan must decide within 72 hours.

Checkpoint: Did the Plan Uphold the Denial?

If the plan confirms the denial after Level 1, you have the right to ask for an independent external review (Level 2). The OIG report did not track external review rates, but CMS data shows that about 40% of external reviews result in overturning the plan’s decision.

Step 3: Escalate to an Independent Review (Level 2)

• Automatic external review? If the plan denies your Level 1 appeal and the case involves a service valued at more than a certain threshold (e.g., $100+), the plan must automatically forward the case to an independent review entity (IRE) unless you waive that right.
• If it’s not automatic: You can request an external review by calling 1-800-MEDICARE (800-633-4227) or through your plan. The IRE must make a decision within 30 days (or 72 hours for urgent cases).
• Success signal: If the IRE overturns the denial, the plan must authorize the service.

Escalation Signals and When to Get Help

• Stop if: You get the service covered at Level 1 or Level 2. No further action needed.
• Escalate if: The service is still denied after external review and is life-threatening or involves a significant delay in care. You can request an expedited hearing or contact the Medicare Beneficiary Ombudsman (1-800-MEDICARE). In rare cases, you may need to file a complaint with CMS (Form OCR-200 or through Medicare.gov).
• Get help from: Your State Health Insurance Assistance Program (SHIP) for free counseling on appeals. SHIP counselors understand plan-specific appeal rules.

Trade-offs and Limitations You Need to Know

Even with a 75% overturn rate, not all denied services are appealable or winnable.

• Non-covered services: If the denial states “this service is not a Medicare-covered benefit,” an appeal will not overturn it. The plan cannot pay for something Medicare explicitly excludes (e.g., most hearing aids, long-term custodial care, cosmetic surgery). Check your Evidence of Coverage to see if the service is a covered benefit.
• Medical necessity disputes: The high overturn rate applies primarily when the plan applies a stricter medical necessity standard than Original Medicare. The OIG report found that many denials were based on plan-specific criteria that didn’t match CMS coverage rules. If your provider can show the service meets Medicare’s national coverage criteria, your odds are excellent. But if the plan’s denial is based on a legitimate benefit exclusion (e.g., a drug not on the formulary with no available exception), the appeal may fail.
• Time-sensitive care: The standard appeal timeline (7 days) may be too slow for conditions that worsen quickly. If you wait for the standard process, the denial could lead to a delay in treatment that causes harm. That’s why you should always request an expedited appeal when the service is time-sensitive. The OIG report does not break down overturn rates by expedited vs. standard, but CMS rules require plans to prioritize urgent cases.

Expert Tips for Maximizing Your Overturn Chances

Tip 1: Ask your doctor to file the appeal on your behalf with a clear medical necessity letter.

• Actionable step: When you receive the denial notice, immediately call your doctor’s office and say, “The plan denied prior authorization for [service]. The OIG report shows 75% of denials are overturned on appeal. Please submit a standard appeal with my medical records within the deadline.” Share the Notice of Denial with them.
• Common mistake to avoid: Assuming your provider will automatically appeal. Many offices rely on automated denial summaries and don’t file appeals unless you explicitly request it.

Tip 2: Keep a written record of every step, including dates and who you spoke with.

• Actionable step: Start a dated log when you first request prior authorization. Write down the date of the denial notice, the deadline for appeal, the date you submitted the appeal, and any plan response. Use a simple notebook or a free app like Notes.
• Common mistake to avoid: Missing the appeal window by not confirming receipt. The plan may claim they sent the appeal form but you never submitted it. Always send by fax with a confirmation page or via certified mail.

Tip 3: Use the expedited appeal route for urgent care, even if the denial doesn’t appear urgent.

• Actionable step: If the denied service is for a condition that could worsen quickly (e.g., a new medication for uncontrolled pain, a procedure to prevent loss of function), tell the plan you need an expedited appeal due to time-sensitive medical need. The plan must respond within 72 hours.
• Common mistake to avoid: Waiting for the standard 7-day timeline when the delay could cause harm. The OIG report shows that some plans don’t automatically flag cases that qualify for expedited handling—you must request it explicitly.

What the OIG Report Means for You

The 2022 OIG findings are not an outlier. A 2023 CMS analysis of 2021 data showed similar trends: 76% of plan-level prior authorization denials were overturned upon appeal. The takeaway is clear: you should never assume a denial is the final word. The largest barrier is not plan resistance—it’s patient and provider inaction.

If you receive a denial, act immediately. Call your doctor, file the appeal, and keep records. The same report also flagged that Black and Hispanic beneficiaries faced higher denial rates for some services, yet appealed at lower rates. CMS now requires plans to submit annual health equity analyses of their utilization management policies, so know that systematic disparities are being monitored—but individual appeals still depend on you.

Important disclaimer: This article is for informational purposes only and does not constitute legal or medical advice. Medicare Advantage plan rules, appeal deadlines, and prior authorization requirements vary by plan and year. Always check your specific Evidence of Coverage and Summary of Benefits. For help, contact 1-800-MEDICARE (TTY 1-877-486-2048) or your State Health Insurance Assistance Program (SHIP). Medicare premiums and plan structures change annually; consult official CMS resources for the most current data.