Experimental or investigational

Experimental / investigational denial appeal letter

Denials labeling a treatment experimental despite FDA approval or peer-reviewed support.

Use this letter to formally appeal a "experimental or investigational" denial. Replace every {{PLACEHOLDER}} with your own facts, attach the listed evidence, and send it certified mail plus by the insurer's online portal.

Template

{{MEMBER_NAME}}
{{MEMBER_ADDRESS}}
{{MEMBER_PHONE}}
Member ID: {{MEMBER_ID}}
Claim / Reference #: {{CLAIM_NUMBER}}
Date of Service: {{DATE_OF_SERVICE}}
Date of Denial Notice: {{DENIAL_DATE}}

{{INSURER_NAME}}
Appeals and Grievances Department
{{INSURER_APPEAL_ADDRESS}}

Re: Formal Internal Appeal — {{CLAIM_NUMBER}}

I am appealing the "experimental or investigational" denial of {{SERVICE_OR_DRUG}} for {{DIAGNOSIS_ICD10}}.

1. {{SERVICE_OR_DRUG}} is FDA-approved for {{FDA_INDICATION}} (see attached FDA label / drug approval letter).

2. The treatment is supported by the following peer-reviewed evidence and clinical guidelines: {{EVIDENCE_LIST}}, including {{NCCN_OR_SOCIETY_GUIDELINE}}.

3. My treating specialist attests that this is standard of care for my clinical picture and that covered alternatives are inappropriate because {{CLINICAL_RATIONALE}}.

Because this is an "experimental/investigational" denial involving a medical judgment, I am also preserving my right to external review under 45 CFR 147.136(d) if this internal appeal is denied.

Sincerely,
{{MEMBER_NAME}}

Key points before you send it

  • Attach FDA labeling or NCCN / peer-reviewed guidelines showing standard-of-care status.
  • External review is available for E/I denials under 45 CFR 147.136(d).
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Not legal or medical advice. This page is a self-help resource. You make your own decisions. Strip personal identifiers (name, date of birth, address, member ID) from any document before uploading or sharing. The information here summarizes commonly-published payer policies and federal rules; confirm against your specific plan document and the current denial letter before acting.