ACA Marketplace Plan Denial Appeals: Your Complete Guide

Unique Protections of ACA Marketplace Plans

ACA Marketplace plans are designed with robust patient protections. Key features include:

• Essential Health Benefits (EHBs): All plans must cover ten categories of EHBs, including hospitalization, prescription drugs, maternity care, mental health, and preventive services. Plans cannot impose annual or lifetime dollar limits on EHBs.
• Preventive care: Many preventive services are covered with no cost-sharing.
• Network adequacy: Plans must maintain networks of providers sufficient to ensure access to all covered services.
• Internal and external appeal rights: These are guaranteed federal rights.

If your denial relates to one of these protected areas, you have a strong appeal argument.

The ACA Appeal Process: What to Expect

The appeal process for ACA plans largely follows the federal standard. Review the full insurance appeal process guide for an overview of all stages.

Key steps for ACA plans:

1. Internal Appeal: You have 180 days from the date of the denial notice to file an internal appeal with your insurer. Your appeal letter should clearly state why you believe the decision was wrong and attach supporting documentation, especially a Letter of Medical Necessity from your doctor.
2. External Review: If your internal appeal is denied, you have 60 days from the date of the final internal denial to request an Independent External Review. This is a powerful step where a neutral third party (an Independent Review Organization, or IRO) reviews your case. If your state does not conduct external reviews, the federal Department of Health and Human Services (HHS) will conduct it. See our external review guide for details.
3. Expedited Appeals: For urgent situations where a delay would seriously harm your health, you can request an expedited internal appeal (72-hour decision) and an expedited external review (72-hour decision). Your doctor must certify urgency.

For denials of premium tax credits or cost-sharing reductions, you appeal directly to the Marketplace, which is a separate process from medical claim appeals.

Common ACA Denial Types and How to Appeal Them

"Not Medically Necessary"

This is the most common denial. Your appeal must include a strong Letter of Medical Necessity from your doctor, outlining your diagnosis, why the treatment is essential, and how it aligns with accepted medical standards. For mental health services, also assert your mental health parity rights.

"Experimental or Investigational"

If an EHB-covered service is denied as experimental, your appeal should include peer-reviewed medical literature, professional society guidelines, and a letter from your doctor establishing that the treatment is generally accepted standard of care. See our experimental treatment denial guide.

Prior Authorization Denial

If a prior authorization for an EHB was denied, your appeal should address why the treatment is medically necessary and challenge any arbitrary prior auth criteria. See our prior authorization appeal playbook.

Out-of-Network Denial

For emergency care or services where no in-network provider was available (network inadequacy), the No Surprises Act and ACA rules protect you. You should not pay more than in-network cost-sharing. See our No Surprises Act guide and out-of-network denial guide.

Utilizing State and Federal Regulators

Beyond formal appeals, you can file complaints with your state Department of Insurance and/or HHS. These complaints put regulatory pressure on your insurer and can sometimes lead to faster resolutions.

For state-specific resources, check our state-by-state appeal guide. To draft your official appeal letter, use our free appeal letter builder and clearly reference the specific ACA provisions that support your claim.