Complete Guide to Aetna's Appeal Process: Internal, Reconsideration, and External Independent Review: Complete Guide" class="auto-link">External Review

Aetna denies millions of claims each year. But a denial is not a final decision — it's an invitation to appeal. Aetna has a multi-level appeal process that, when navigated correctly, results in overturned denials a significant portion of the time. This guide walks you through every level.

Who Is Aetna?

Aetna is the third-largest health insurer in the United States, covering approximately 23 million medical members. Since its acquisition by CVS Health in 2018, Aetna operates as a CVS Health subsidiary, with pharmacy benefits administered through CVS Caremark. Aetna administers both fully insured commercial plans (regulated by state insurance departments) and self-funded employer plans (governed by federal ERISA law).

Understanding which type of plan you have is crucial — it determines which appeals process applies and which external review rights you have.

Before You Appeal: Get the Right Documents

Before filing any appeal, obtain:

1. Denial letter (EOB)" class="auto-link">Explanation of Benefits or formal denial notice): Contains the reason code, the specific criteria not met, and your appeal deadline
2. Aetna's Clinical Policy Bulletin (CPB): For the denied service. Available at aetna.com/health-care-professionals. The CPB contains the exact criteria Aetna uses.
3. Your Summary Plan Description (SPD): Defines your coverage, exclusions, and appeal rights. Request from HR or through my.aetna.com.
4. Your medical records: Request from your provider. Every page of documentation that supports your case.
5. InterQual or MCG criteria (for utilization denials): Request from Aetna in writing — you are entitled to the specific criteria used to deny your claim.

Level 1: Internal Appeal

The internal appeal is your first formal step. Aetna allows members to submit an internal appeal within 180 days of receiving a denial (some plans allow less — check your denial letter).

What to include:

• A clear cover letter stating you are filing an appeal and the specific denial you are contesting
• Medical records supporting the necessity of the denied service
• Your physician's letter of medical necessity, specifically addressing Aetna's CPB criteria
• Peer-reviewed clinical literature supporting your treatment
• Any other evidence not previously submitted

How to file:

• Phone: 1-800-537-9384
• Online: my.aetna.com (member portal — allows document upload)
• Written mail: Aetna Appeals, P.O. Box 981106, El Paso, TX 79998

Timelines:

• Standard appeal: Decision within 30 days for pre-service denials, 60 days for post-service (after-care) denials
• Expedited appeal: Decision within 72 hours for urgent situations (request this explicitly if your health is at immediate risk)

Level 2: Reconsideration / Second-Level Appeal

Aetna offers a second-level internal appeal (sometimes called "reconsideration") for members who receive an adverse determination on their first-level appeal. This is reviewed by a different medical reviewer than the first level.

At this level, focus on:

• Any new clinical evidence or medical literature not submitted in the first appeal
• A stronger physician advocacy letter that specifically rebuts Aetna's denial reasoning
• Requesting a peer-to-peer review — your physician can call Aetna's medical director directly at 1-866-752-7021 to discuss the case clinically

Timelines for second-level appeals are generally the same as first-level: 30–60 days for standard, 72 hours for expedited.

iro">Level 3: External Independent Review (IRO)

If Aetna's internal appeals fail, you have the right to an external independent review. For most Aetna plans, the external IRO is Maximus Federal Services, which provides independent clinical review by physicians with no connection to Aetna.

Key facts about external review:

• You must exhaust internal appeals first (or Aetna must waive this requirement)
• The IRO's decision is binding on Aetna for clinical necessity determinations
• External review is free to you (no cost)
• The IRO reviews only clinical/medical necessity questions, not contract interpretation

How to request external review:

• Contact Aetna at 1-800-537-9384 and request external independent review after exhausting internal appeals
• Aetna will send you an external review request form and instructions
• You may also file directly with Maximus through Aetna's external review program

External review timelines:

• Standard: 45 days from request
• Expedited: 72 hours from request

Expedited Appeals: When You Need an Urgent Decision

Request an expedited appeal when:

• Your health, life, or ability to regain maximum function would be seriously jeopardized by a standard review timeline
• You are currently in the hospital and Aetna is denying continued care
• A treatment must begin immediately to be effective

For expedited appeals, call Aetna at 1-800-537-9384 and use the words "expedited review" and "urgent medical situation." Follow up in writing.

Concurrent Review and Hospital Stay Denials

If Aetna is denying coverage for an ongoing hospital stay (concurrent review), you have the right to continue receiving care during the appeal process without fear of discharge. Request expedited review immediately and have your attending physician contact Aetna's medical director for a peer-to-peer review.

Documentation That Wins Aetna Appeals

The appeals that succeed share common elements:

• Specificity: Address Aetna's exact denial reason, not general medical necessity
• CPB alignment: Show that your case meets Aetna's own CPB criteria
• Physician voice: A doctor's letter carries more weight than a member letter alone
• Literature support: Cite peer-reviewed guidelines (NCCN, ADA, AAFP, ACC)
• Completeness: Every relevant page of your medical record, organized and tabbed

After All Appeals Fail: Additional Remedies

If all Aetna appeals are exhausted, you still have options:

• State Department of Insurance complaint: For fully insured plans (not ERISA self-funded)
• DOL EBSA complaint: For self-funded ERISA plans (dol.gov/agencies/ebsa)
• CMS complaint: For Medicare Advantage plans (medicare.gov/claims-appeals)
• State Insurance Commissioner mediation: Available in many states
• Legal action: ERISA allows lawsuits for wrongful benefit denials (consult an ERISA attorney)

Fight Back With ClaimBack

The Aetna appeals process is designed to be navigated — and ClaimBack gives you the tools to do it effectively. We help you write appeals that speak Aetna's language, address their CPB criteria, and present your case in the format that gets results.

Start your Aetna appeal with ClaimBack

Related Reading

• How to Write an Insurance Appeal Letter
• Internal vs. External Insurance Appeals
• What Is Medical Necessity?