Insurance Appeal Letter Template – Free Download 2026

DATE: [____________]. TO: [____________] ("Insurer"), Appeals Department, [____________] (Address). FROM: [____________] ("Policyholder" / "Claimant"), [____________] (Address). RE: Formal Appeal of Claim Denial — Policy No. [____________] / Claim No. [____________] / Date of Service: [____________] / Date of Denial: [____________]. I am writing to formally appeal the denial of the above-referenced claim (the "Denied Claim"), a copy of your denial letter dated [____________] is attached hereto as Exhibit A. I respectfully request that you reconsider and reverse the denial and provide coverage and/or reimbursement as set forth below.

The Denied Claim involves [medical services / property damage / disability / life insurance proceeds / other: ____________] provided to [____________] by [____________] (the "Provider") on or about [____________]. The services at issue involved [____________]. Your denial letter states the basis for denial as: "[____________]." I dispute this determination as legally and factually incorrect for the reasons set forth in this appeal. The total amount in dispute is [$__________].

[Medical Necessity:] The denial on grounds of medical necessity is contrary to the clinical evidence and applicable standards of care. The [treatment / procedure / service / medication / equipment] at issue was medically necessary as defined under Policy Section [______] and applicable law because: [____________]. Attached hereto as Exhibit B is a letter of medical necessity from [Dr./Provider Name], [Specialty], dated [____________], confirming that the [treatment/service] was medically necessary and consistent with generally accepted standards of care for the diagnosis of [____________] (ICD-10 Code: [____________]). [Policy Coverage:] The Policy provides coverage for [____________] under [Section/Rider] [______], and the Denied Claim falls squarely within this covered benefit. Your denial misinterprets or misapplies the policy language because: [____________].

[Factual Error:] The denial appears to be based on factual errors, including: (a) [incorrect date of service / incorrect provider / incorrect diagnosis code / incorrect procedure code / other: ____________]; (b) [incorrect application of deductible, out-of-pocket maximum, or coordination of benefits]; and/or (c) [failure to consider prior authorization obtained on ____________, Authorization No. ____________]. The correct facts are: [____________]. Under [applicable state insurance code / ERISA, 29 U.S.C. § 1132 / ACA, 42 U.S.C. § 18001 et seq. / other applicable law], the insurer is required to provide full and fair consideration of all relevant evidence, and a denial based on factual error constitutes an abuse of discretion and an arbitrary and capricious determination subject to reversal.

In support of this appeal, I am submitting the following documentation: (a) Exhibit A — Copy of Insurer's denial letter dated [____________]; (b) Exhibit B — Letter of medical necessity / clinical justification from [____________] dated [____________]; (c) Exhibit C — Medical records and treatment notes for dates of service [____________] through [____________]; (d) Exhibit D — Applicable policy provisions, certificate of coverage, and summary plan description; (e) Exhibit E — Prior authorization approval dated [____________], Authorization No. [____________]; (f) Exhibit F — [Peer-reviewed literature / clinical guidelines / other supporting evidence: ____________]; and (g) Exhibit G — [Other: ____________]. I reserve the right to supplement this record with additional documentation.

I request that the reviewer assigned to this appeal have appropriate clinical expertise in the relevant specialty and have no prior involvement in the initial denial decision. Pursuant to [applicable state law / ERISA / ACA], I am entitled to a full and fair review by a qualified appeals reviewer. If the reviewer intends to rely on any new clinical criteria, evidence, or rationale not set forth in the original denial letter, I request that I be provided with a copy of such materials and an opportunity to respond prior to the issuance of the appeal determination.

I hereby request that the Insurer: (a) immediately reverse the denial and approve the Denied Claim for payment in full in the amount of [$__________]; (b) issue payment directly to [Provider / me] within [thirty (30)] days of this appeal determination; (c) provide a written explanation of the appeal determination, including the specific clinical criteria applied and the basis for any continued denial; and (d) preserve all documents, records, and communications related to the Denied Claim and this appeal in accordance with applicable record retention requirements.

If my internal appeal is unsuccessful, I intend to exercise all available external appeal and regulatory rights, including: (a) requesting an independent external review pursuant to [applicable state external appeal law / ACA Section 2719 / 45 C.F.R. § 147.136]; (b) filing a complaint with the [State Department of Insurance / State Insurance Commissioner]; (c) filing a complaint with the [U.S. Department of Labor Employee Benefits Security Administration (for ERISA plans)]; and (d) pursuing all other available legal remedies, including filing an action under [ERISA § 502(a) / applicable state contract and bad faith insurance law] to recover benefits due, attorneys' fees, and any other relief to which I may be entitled. This letter constitutes a formal notice of appeal and a reservation of all rights.