What Is an Insurance Appeal?
When your insurance denies a claim or refuses to cover a service, you have the right to challenge that decision through an appeal. Insurance companies deny claims regularly — but many denials are overturned when appealed. Studies show that 40-60% of appeals are successful.
Common Reasons for Denial
- Service deemed "not medically necessary"
- Prior authorization not obtained
- Provider was out-of-network
- Service is an exclusion under your plan
- Billing or coding error
- Missing documentation
The Appeals Process
Step 1: Internal Appeal
File a written appeal with your insurance company within 180 days of the denial. Include:
- Your denial letter (the EOB showing the denied claim)
- A letter from your doctor explaining medical necessity
- Medical records supporting the treatment
- Any relevant clinical guidelines or studies
The insurer must respond within 30 days (72 hours for urgent care).
Step 2: External Review
If your internal appeal is denied, you can request an external review by an independent third party. This reviewer is not affiliated with your insurance company. Their decision is binding on the insurer.
Always appeal. Most people accept denials without challenging them. But insurance companies frequently overturn denials when presented with supporting documentation. Your doctor's office often has staff experienced with appeals — ask them to help. The appeal process is free and applies to all ACA-compliant plans (marketplace and private).
Related Terms
Last updated: March 30, 2026.
