Aetna Claim Denied: How to Appeal Your Aetna Health Insurance Decision

Aetna Claim Denied: How to Appeal Your Aetna Health Insurance Decision

Aetna is one of the largest health insurers in the United States, serving tens of millions of members through employer-sponsored plans, individual and family plans, Medicare, and Medicaid. Aetna denies a significant number of claims each year — but under the Affordable Care Act (ACA) and applicable state laws, you have strong, legally guaranteed rights to appeal. This guide explains exactly how to use them.

About Aetna

Aetna Inc. is now a subsidiary of CVS Health, having been acquired in 2018. Despite the corporate restructuring, Aetna continues to operate as one of America's "Big Five" health insurers alongside UnitedHealth, Cigna, Humana, and Anthem/Elevance. Aetna offers:

• Employer-sponsored group health insurance (the largest segment)
• Individual and family plans on ACA Marketplace
• Medicare Advantage plans
• Medicaid managed care plans

The appeal process varies somewhat depending on which type of plan you have, but the core rights are similar for most.

Common Aetna Claim Denial Reasons

Medical necessity denials: This is the most common type of Aetna denial. Aetna's clinical reviewers determine that the treatment, procedure, or service was not medically necessary according to Aetna's own clinical policy bulletins. Examples include:

• Denial of inpatient admission (Aetna argues outpatient treatment is sufficient)
• Denial of specific procedures (Aetna argues alternatives are available)
• Denial of specialist referrals or diagnostic tests

Prior authorization denials: Many services require Aetna's pre-approval before you receive them. If prior authorization was not obtained, or if Aetna denied the authorization request, the subsequent claim will be denied. This is particularly common for imaging (MRI, CT), specialty drugs, surgical procedures, and mental health services.

Out-of-network provider denials: If you received care from a provider who is not in Aetna's network, your claim will be denied (for HMO plans) or paid at a lower out-of-network benefit rate (for PPO plans). Under the No Surprises Act (effective 2022), surprise billing for certain emergency services and some facility-based care is prohibited, which provides significant federal protection.

Coverage exclusion denials: Aetna's plans exclude certain services — commonly cosmetic procedures, experimental treatments, dental and vision care (in medical plans), and certain mental health services (though mental health parity rules under the Mental Health Parity and Addiction Equity Act, MHPAEA limit these exclusions).

Coding and billing errors: Hospital and physician billing codes (ICD-10, CPT codes) can be entered incorrectly, causing claims to appear to fall outside covered benefits when they actually do not. If the claim involves billing codes, ask for an explanation of what was billed versus what was submitted.

Exceeding benefit limits: Some Aetna plans impose day limits (on inpatient stays), visit limits (on therapy visits), or dollar limits (on certain services). Claims beyond these limits are denied.

Your ACA Appeal Rights: What the Law Guarantees

Under the ACA (and the Employee Retirement Income Security Act, ERISA, for employer plans), you have the following legally guaranteed rights when Aetna denies a claim:

1. Right to a written denial notice: Aetna must tell you in writing why your claim was denied, the specific plan provision or clinical standard it relied on, and your right to appeal.

2. Right to your claim file: You have the right to request a copy of your entire claim file, including the clinical guidelines Aetna used to make its decision, at no cost.

3. Right to an internal appeal:

• Standard appeals: Aetna must decide within 60 days
• Urgent/expedited appeals (where delay would cause serious harm): Aetna must decide within 72 hours

4. Right to an external review by an independent organisation:

• After exhausting your internal appeal, you can request external review by an Independent Review Organisation (IRO) appointed by your state's Department of Insurance (or by the federal government for self-insured plans)
• IRO decisions are binding on Aetna
• The federal external review program requires a decision within 60 days (45 days for standard review, 72 hours for expedited)
• External review is free for consumers

5. Right to file a complaint with your state's Department of Insurance: You can file a complaint with your state regulator regardless of whether you are also pursuing an appeal. Your state's insurance commissioner has authority to investigate Aetna's claims practices.

Step-by-Step: Appealing an Aetna Claim Denial

Step 1: Review the Denial Notice Carefully

Aetna's denial notice (Explanation of Benefits, or EOB) must specify:

• The reason for denial
• The clinical policy bulletin or plan provision relied on
• Instructions for appealing

Read every word. The denial reason dictates your entire appeal strategy.

Step 2: Request Your Claim File

Call Aetna Member Services (number on your insurance card) or log into aetna.com and request a copy of your full claim file. This file should include the clinical guidelines and criteria Aetna used to deny the claim. Review these criteria carefully — your appeal must address them directly.

Step 3: Gather Supporting Medical Evidence

For a medical necessity appeal:

• A detailed letter from your treating physician explaining why the treatment is medically necessary, why alternatives are not appropriate, and citing clinical guidelines from recognised bodies (ACP, AAFP, ACS, etc.)
• Medical records supporting the diagnosis
• Peer-reviewed journal articles supporting the treatment

For a prior authorization dispute:

• Documentation showing authorization was requested
• Evidence that the authorization process was followed correctly
• Any communications with Aetna about the authorization

For coding/billing disputes:

• Corrected billing codes with a letter from the provider explaining the correction

Step 4: Submit Your Aetna Internal Appeal

Write a formal appeal letter to Aetna's Appeals and Grievances department. Address every denial ground directly. Include all supporting documentation.

Aetna Appeals Contact:

• Online portal: aetna.com (member portal)
• Mail: Check your Aetna plan documents or denial notice for the specific address for your plan type
• Phone: 1-800-872-3862 (Aetna Member Services — ask for the appeals department)

ClaimBack at claimback.app generates a professionally structured, ACA-compliant appeal letter for Aetna claim denials. The tool helps you address Aetna's clinical criteria directly and present your physician's evidence in the most persuasive format.

Step 5: Request Expedited Appeal (If Applicable)

If waiting 60 days would seriously jeopardise your life or health, request an expedited internal appeal. Aetna must respond within 72 hours for urgent care situations.

Step 6: Request External Review

If Aetna's internal appeal decision upholds the denial, immediately request an external review by an Independent Review Organisation (IRO). You have 4 months from Aetna's final appeal decision to request external review (check your state's specific deadline, as some are shorter).

To request external review:

1. Contact Aetna and request external review initiation (Aetna should provide instructions in the appeal denial letter)
2. Or contact your state's Department of Insurance directly for self-insured ERISA plans (these go through a federal external review process)

External review outcomes for medical necessity denials favour consumers a substantial proportion of the time — in some states, 40-60% of external reviews result in decisions for the consumer.

Step 7: File with Your State Insurance Commissioner

File a complaint with your state's Department of Insurance (find your state regulator at naic.org). State regulators have authority to investigate Aetna's claims practices and can apply regulatory pressure that sometimes independently resolves individual disputes.

Aetna-Specific Timelines

Action	Deadline
Aetna standard internal appeal decision	60 days from appeal submission
Aetna expedited internal appeal decision	72 hours from appeal submission
Request for external review (post-appeal)	Within 4 months of Aetna's final appeal decision
External review decision (standard)	45 calendar days
External review decision (expedited)	72 hours

Common Mistakes in Aetna Appeals

Not requesting the clinical guidelines: Aetna's internal clinical policy bulletins define "medical necessity" for hundreds of procedures. If you don't know what criteria Aetna is applying, you cannot address them in your appeal.

Missing the external review deadline: The 4-month (or shorter state-specific) deadline for requesting external review is strictly enforced. Request external review immediately after Aetna's final appeal decision.

Relying on a GP letter instead of a specialist letter: Aetna's clinical reviewers are specialists. A letter from your primary care physician is much less persuasive than one from a board-certified specialist in the relevant field.

Not using the mental health parity law: If your claim involves mental health or substance use disorder treatment, the MHPAEA requires Aetna to apply comparable standards to mental health benefits as it does to medical/surgical benefits. Many mental health denials violate this law.

Conclusion

An Aetna claim denial is not final. The ACA guarantees you the right to a free internal appeal and a free external review — and external review decisions are binding on Aetna. The key is a well-structured, evidence-based appeal that directly addresses Aetna's stated denial criteria. Use ClaimBack at claimback.app to generate a professional, ACA-compliant appeal letter, escalate to external review, and file a complaint with your state's Department of Insurance. Persist — a significant proportion of appealed Aetna denials are overturned.