Aetna Medicare Advantage Claim Denied — Appeal Guide
Aetna Medicare Advantage denied your claim? Here's how to use Aetna's MA appeal process and escalate through the CMS appeals ladder.
Aetna Medicare Advantage Claim Denied — Appeal Guide
Aetna is one of the largest Medicare Advantage insurers in the United States, offering HMO, PPO, and Dual Eligible Special Needs Plans (D-SNP) under the Aetna Medicare brand. CVS Health completed its acquisition of Aetna in 2018, so you may see the CVS Health name in some communications — but the appeal rights are the same.
If Aetna denied your claim or Prior Authorization Denied: How to Appeal" class="auto-link">prior authorization, federal law gives you the right to challenge that decision through a structured appeals process. Here's how to use it.
Common Aetna Medicare Advantage Denial Reasons
Aetna's clinical reviewers apply proprietary criteria that sometimes result in denials even when your physician recommends a service. The most frequent reasons include:
- Prior authorization denied: Aetna determined the service doesn't meet its criteria for medical necessity, often without reviewing your full clinical history.
- Out-of-network care: HMO members generally must use Aetna's network; care outside it may be denied except in emergencies.
- Not medically necessary: The requested service, procedure, or equipment was deemed not medically necessary based on Aetna's clinical guidelines.
- Step therapy requirements: Aetna may require you to try and fail less expensive treatments before approving a preferred medication or procedure.
- Custodial vs. skilled care: Aetna may classify care as custodial (not covered) when your doctor says it qualifies as skilled care.
- D-SNP-specific issues: Dual eligible members may face coordination-of-benefits denials when Medicaid and Medicare coverage overlap.
No matter the stated reason, you have the right to appeal.
Aetna Medicare Advantage Appeal Timelines
CMS federal regulations bind Aetna to specific decision timelines:
- Expedited (urgent) appeals: Aetna must respond within 72 hours for prior authorization requests and within 24 hours for coverage decisions when your health is at serious risk.
- Standard appeals: Aetna must decide within 30 days for PA requests and 60 days for post-service claim appeals.
If Aetna misses these deadlines, the failure is automatically escalated as a favorable ruling in some circumstances, and you can file a CMS complaint at any time.
Step 1 — Peer-to-Peer Review
Ask your physician to request a peer-to-peer review — a direct clinical conversation with Aetna's medical director or reviewer. Many denials are resolved at this stage, especially when the treating physician can walk through the clinical evidence in real time. Peer-to-peer requests typically must be made within a short window after denial, so act quickly.
Step 2 — Level 1 Internal Appeal (Part C Reconsideration)
File your Level 1 appeal directly with Aetna. Your denial notice will include the mailing address, fax number, or online portal for submitting appeals.
Your appeal package should include:
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- A copy of the Aetna denial notice
- A detailed letter of medical necessity from your treating physician
- Relevant clinical records supporting the service (diagnosis codes, treatment history, test results)
- Any relevant clinical guidelines that support coverage
Request expedited review if waiting the standard timeframe would harm your health. Aetna must make its Level 1 decision within the required CMS timeframe.
Step 3 — Level 2 External Independent Review: Complete Guide" class="auto-link">External Review (MAXIMUS Federal Services)
If Aetna upholds the denial, you have the right to an independent external review by MAXIMUS Federal Services, contracted by CMS to provide unbiased review of MA plan decisions. MAXIMUS reviewers apply Original Medicare coverage standards — not Aetna's proprietary criteria.
- Standard MAXIMUS review: 60 days
- Expedited MAXIMUS review: 72 hours
MAXIMUS contact information and instructions will be included in Aetna's Level 1 denial letter. This external review step overturns MA plan decisions at a meaningful rate — always pursue it if Aetna denies your Level 1 appeal.
Levels 3, 4, and 5 — Escalating Further
If MAXIMUS upholds the denial and the disputed amount meets the minimum threshold (approximately $180 for an ALJ hearing), you may continue up the appeals ladder:
- Level 3: ALJ hearing through the Office of Medicare Hearings and Appeals (OMHA)
- Level 4: Medicare Appeals Council review
- Level 5: Federal District Court
Each level requires filing within specific deadlines from the prior decision. Keep meticulous records of all correspondence and decisions.
Free Help from SHIP Counselors
State Health Insurance Assistance Programs (SHIP) provide free Medicare counseling to beneficiaries. SHIP advisors can review your denial letter, help you organize your appeal, and explain your rights under the federal MA framework. Call 1-800-MEDICARE (1-800-633-4227) to be connected to your state's SHIP.
Strategies for a Successful Aetna MA Appeal
- Address Aetna's stated reason head-on: Read the denial letter carefully and build your appeal around refuting each specific reason cited.
- Quote Original Medicare coverage standards: Aetna MA plans must cover anything Original Medicare covers. If your service is covered under Original Medicare, cite the relevant Medicare National Coverage Determination (NCD) or Local Coverage Determination (LCD).
- Get specific clinical support: Vague letters of medical necessity are easy to deny. Ask your doctor to provide detailed documentation linking your diagnosis to the specific treatment requested.
- Request everything in writing: Verbal communications don't count. Every denial and appeal response should be documented in writing.
- Act within deadlines: You typically have 60 days from the denial notice to file each appeal level.
Fight Back With ClaimBack
Aetna Medicare Advantage denials can be overturned — but the process is detailed and time-sensitive. ClaimBack helps you prepare a complete, well-supported appeal so you don't miss critical steps or deadlines.
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