July 19, 2026

Appeals Department
[Insurance company name]

Re: Formal Appeal of Claim Denial
Member ID: [Member ID]
Claim Number: [Claim number]
Date of Service: [Date of service]

To Whom It May Concern,

I am formally appealing the denial of the above-referenced claim for services rendered at the provider. The denied service was ordered by my treating physician as medically necessary for my diagnosis. I have attached a Letter of Medical Necessity from my provider explaining why this treatment is appropriate and why alternative or more conservative treatments are insufficient or have already been tried.

Please reprocess this claim and issue a written determination of the appeal within the timeframe required by my plan and applicable state and federal law (including ERISA and the Affordable Care Act, where applicable).

Attached supporting documentation:
- [ ] Copy of the original Explanation of Benefits (EOB)
- [ ] Letter of Medical Necessity from my treating physician
- [ ] Relevant medical records and chart notes
- [ ] Peer-reviewed clinical guidelines (if applicable)

If this internal appeal is denied, please be advised that I intend to pursue an external review through my state's insurance regulator. Thank you for your prompt attention to this matter.

Sincerely,

[Your full name]

Template only. Send by certified mail or your insurer's secure portal so you have proof of submission. Most plans require internal appeals within 180 days of denial.