How to Appeal an Aetna Denial — Step-by-Step Guide

Aetna, now a subsidiary of CVS Health, is one of the largest health insurance companies in the United States, covering more than 34 million people. Like all major insurers, Aetna denies claims regularly — but their denial is rarely the final word. You have strong rights to appeal, and the process is more straightforward than most people think.

This guide covers the specific Aetna appeal process, including their timelines, contact information, and the strategies most likely to get your denial overturned.

Step 1: Decode Your Aetna Denial

Aetna denial letters (formally called "Adverse Benefit Determinations") must include specific information required by law:

• Denial reason — The specific reason your claim was denied, including clinical rationale if applicable
• Plan provisions — The section of your plan that Aetna cites as justification
• Appeal instructions — How and where to file your appeal, with deadlines
• Your rights — Including the right to request Aetna's clinical criteria and any internal documents used in the decision

Common Aetna denial reasons include:

• Not medically necessary — Aetna's clinical reviewers determined the service doesn't meet their criteria
• Not a covered benefit — The service isn't included in your specific plan
• Prior authorization required — Pre-approval wasn't obtained before the service
• Out-of-network — The provider isn't in Aetna's network for your plan
• Timely filing exceeded — The provider submitted the claim too late

Understanding the denial reason is critical because your appeal strategy depends entirely on it. If you're having trouble interpreting the letter, our guide to reading an EOB can help.

Step 2: Contact Aetna and Gather Information

• Aetna Member Services: 1-800-872-3862 (or the number on your ID card)
• Aetna Online Portal: aetna.com — view claims, denial details, and submit appeals
• Aetna Mobile App: Available for iOS and Android — check claim status on the go

When you call, ask these questions:

1. "What specific clinical criteria or policy did you use to deny my claim?"
2. "Can you send me a copy of Aetna's Clinical Policy Bulletin for this service?"
3. "How many levels of internal appeal does my plan have?"
4. "Can my doctor request a peer-to-peer review with your medical director?"
5. "What is my exact deadline to file an appeal?"

Important: Document every call — date, time, representative's name, reference number, and what was discussed. This creates a paper trail you may need later.

Step 3: Build Your Appeal

Get your doctor involved

Your physician is your most powerful ally in an Aetna appeal. Ask them to:

1. Write a letter of medical necessity — This should detail your diagnosis, treatment history, why the denied service is necessary, and why alternatives won't work
2. Request a peer-to-peer review — Aetna allows your doctor to speak directly with an Aetna medical director. This is often the fastest path to reversal, especially for medical necessity denials
3. Provide clinical evidence — Published guidelines, peer-reviewed studies, and specialist opinions supporting the treatment

Research Aetna's own criteria

Aetna publishes its Clinical Policy Bulletins (CPBs) online at aetna.com/health-care-professionals/clinical-policy-bulletins. These are the exact criteria Aetna's clinical reviewers use to make coverage decisions. If your case meets the criteria in the relevant CPB, cite it explicitly in your appeal — it's hard for Aetna to deny a claim that meets their own published standards.

Prepare your appeal letter

Use our free appeal letter template and customize it for Aetna. Your letter should:

• Include your member ID, group number, claim number, and date of service
• State clearly that you are filing a formal appeal under your plan's appeal process
• Address the specific denial reason point by point
• Reference Aetna's Clinical Policy Bulletin by name and number
• List every supporting document you're including
• Request a written response within the required timeframe

Step 4: File Your Internal Appeal with Aetna

By mail

Aetna
Attn: National Appeals Unit
P.O. Box 14463
Lexington, KY 40512-4463

Note: Your plan may have a different appeal address. Always use the address on your denial letter.

By fax

Fax to the number on your denial letter. Keep the fax confirmation as proof.

Online

Log in at aetna.com, navigate to your claims, and look for the appeal option. You can upload documents directly through the portal.

By phone

For urgent appeals, you can initiate the process by calling Aetna Member Services at 1-800-872-3862. Follow up with written documentation.

Aetna appeal timelines

Two levels of internal appeal: Many Aetna plans have two levels of internal appeal. If your first-level appeal is denied, you typically have 60 days to file a second-level appeal. Check your plan documents or call Aetna to confirm how many levels your plan requires before you can request external review.

Step 5: External Review If Aetna Upholds the Denial

After exhausting Aetna's internal appeal process, you have the right to an independent external review:

1. Request external review within 4 months of your final internal appeal denial
2. An Independent Review Organization (IRO) with relevant medical expertise reviews your case
3. The IRO makes a decision within 45 days (72 hours for urgent cases)
4. If the IRO rules in your favor, Aetna must cover the claim — the decision is legally binding

Expedited external review: If your health is in immediate jeopardy, you can request expedited external review simultaneously with your internal appeal. The IRO must decide within 72 hours.

Your Rights Under the No Surprises Act

The No Surprises Act gives Aetna members additional protections:

• Emergency care: Aetna cannot deny emergency room claims based on out-of-network status or prior authorization requirements. You can only be charged in-network cost-sharing for emergency care.
• Surprise billing: If you received care at an in-network Aetna facility from an out-of-network provider you didn't choose (such as an anesthesiologist, pathologist, or assistant surgeon), Aetna must cover it at in-network rates.
• Good faith estimates: Uninsured or self-pay patients can request a Good Faith Estimate and dispute bills exceeding the estimate by $400+.
• Federal IDR: For surprise billing disputes, use the federal Independent Dispute Resolution process at cms.gov/nosurprises.

File a Complaint with Your State Insurance Commissioner

Filing a complaint with your state insurance department adds regulatory pressure and can expedite the resolution of your appeal. Insurers take state regulatory inquiries very seriously.

• Find your state department at the NAIC directory
• Most states accept online complaints
• Include your denial letter, appeal documentation, and any correspondence with Aetna

Key states where Aetna has major presence:

• Connecticut: Insurance Department at 1-800-203-3447 (Aetna's home state)
• Texas: Department of Insurance at 1-800-252-3439
• Florida: Office of Insurance Regulation — file online at floir.com
• New Jersey: Department of Banking and Insurance at 1-800-446-7467
• Pennsylvania: Insurance Department at 1-877-881-6388

Self-funded employer plans: If your Aetna coverage is through a large employer's self-funded plan, contact the U.S. Department of Labor, Employee Benefits Security Administration at 1-866-444-3272. Self-funded plans are regulated by federal ERISA law, not your state insurance department.

Common Aetna Denial Reasons and How to Fight Them

"Not medically necessary"

Look up Aetna's Clinical Policy Bulletin (CPB) for your specific service. If your case meets the published criteria, quote it verbatim in your appeal. Have your doctor write a letter addressing each criterion. Include peer-reviewed studies and medical society guidelines. Request a peer-to-peer review between your doctor and Aetna's medical director.

"Prior authorization required"

Ask your provider to submit a retroactive prior authorization request. If the provider failed to get prior auth, argue that you (the patient) should not be penalized for the provider's administrative error. Many state laws protect patients in this situation. Learn more about how prior authorization works.

"Not a covered benefit"

Review your Summary of Benefits and Coverage (SBC) and full plan document carefully. Sometimes a service is covered under a different category or billing code. Ask your provider about alternative CPT codes that might be covered. Also check whether the ACA requires coverage of the service — Aetna ACA-compliant plans must cover all Essential Health Benefits.

"Timely filing"

If the provider submitted the claim after Aetna's filing deadline, this is typically the provider's problem, not yours. Contact the provider's billing department and ask them to refile or appeal on their behalf. You generally should not be held responsible for a provider's timely filing failure — the provider cannot bill you for a claim they failed to submit on time.

When to Get Professional Help

• Patient Advocate Foundation: Free case management at 1-800-532-5274 or patientadvocate.org
• State Consumer Assistance Programs: Free help navigating insurance appeals — find yours at cms.gov
• Healthcare attorneys: For large claims or ERISA disputes, an attorney experienced in health insurance law can significantly improve your odds. Many offer free initial consultations.
• Medical billing advocates: Use Taven's bill review tool to identify billing errors first, then consider a professional advocate for complex situations.

Seek professional help when:

1. The denied amount exceeds $5,000
2. You've lost your first internal appeal
3. The denial involves complex medical treatments or experimental procedures
4. You have a self-funded ERISA plan
5. The denial is for ongoing, life-sustaining, or urgent care

Aetna Appeal Checklist

1. Read your denial letter and note the reason, deadline, and appeal address
2. Call Aetna Member Services and request the Clinical Policy Bulletin used in the denial
3. Ask your doctor to request a peer-to-peer review with Aetna's medical director
4. Get a detailed letter of medical necessity from your treating physician
5. Research Aetna's Clinical Policy Bulletin for your service at aetna.com
6. Write your appeal using our free appeal template
7. Submit by mail, fax, or online portal (keep proof of delivery)
8. Follow up within 2 weeks if you haven't received confirmation
9. If first-level appeal is denied, file second-level appeal within 60 days
10. If all internal appeals fail, request independent external review within 4 months
11. File a complaint with your state insurance department for additional leverage

The Bottom Line

Aetna denies millions of claims, but their denial process is designed to be challenged. With Aetna's Clinical Policy Bulletins publicly available, you can build a precise, evidence-based appeal that addresses the exact criteria they use. Combined with your doctor's support and the power of external review, you have real tools to fight back.

Remember: most people never appeal their denied claims. Just by filing an appeal, you're taking a step that the vast majority of denied members skip. And with roughly half of appeals succeeding, the odds are better than you think.

For more help, read our complete guide to fighting hospital bills or use Taven's bill review tool to make sure you're not being overcharged in the first place.