CARC 50 appeal letter template — Not Medically Necessary

CARC 50 means the payer determined the billed service is a non-covered service because it was not deemed medically necessary; this template helps providers appeal by submitting clinical documentation supporting the necessity of the service.

When to appeal vs. correct & resubmit

Appeal CARC 50 when you have clinical documentation (history, exam findings, prior conservative treatment, diagnosis-to-procedure linkage, or guideline support) that establishes the service met the payer's medical necessity criteria. If the claim was billed with an incorrect or incomplete diagnosis code, missing modifier, or wrong CPT/HCPCS code that misrepresented the clinical picture, correct and resubmit the claim instead of appealing. If no supporting clinical rationale exists for the service rendered, an appeal is unlikely to be appropriate.

Appeal letter template

Copy the template, replace every [bracketed] field with your details, and keep only the paragraph that fits your situation.

[Date]

[Payer Name]
Appeals Department
[Payer Address]

Re: Appeal of Denied Claim — CARC 50 (Not Medically Necessary)
Patient Name: [Patient Name]
Member ID: [Member ID]
Claim Number: [Claim #]
Date of Service: [DOS]
Provider: [Provider Name, NPI]
CPT/HCPCS Code(s): [CPT/HCPCS]
Authorization #: [Authorization #]

Dear Appeals Reviewer,

This letter serves as a formal appeal of the above-referenced claim, which was denied under CARC 50, indicating the service was considered a non-covered service because it was not deemed a medical necessity by the payer.

We respectfully disagree with this determination and request reconsideration based on the enclosed clinical documentation. The service(s) billed under [CPT/HCPCS] were rendered for the following clinical reasons: [insert clinical rationale, relevant diagnosis, symptoms, prior treatments, or guideline support]. This documentation supports that the service was reasonable and necessary for the diagnosis and treatment of the patient's condition on [DOS].

Enclosed please find supporting documentation, including relevant medical records, clinical notes, and any prior authorization or guideline references, which we believe substantiate the medical necessity of the service(s) provided.

We ask that the payer reevaluate this claim in light of the enclosed information and reverse the CARC 50 denial. Please contact our office at [Phone] or [Email] if additional information is needed to complete this review.

Thank you for your attention to this appeal.

Sincerely,
[Provider Name, NPI]
[Practice Name]
[Phone]
[Email]

What to attach

• Copy of the EOB/ERA showing CARC 50 denial
• Relevant medical records and clinical notes supporting necessity
• Physician's letter of medical necessity, if applicable
• Prior authorization documentation, if obtained
• Applicable clinical guidelines or payer medical policy referenced by the treating provider
• Diagnostic test results or imaging reports supporting the diagnosis

Frequently asked questions

More free billing tools: all appeal letters · denial codes · NCCI edits · Medicare fees

This template is provided for informational purposes only and does not constitute legal, medical, or billing advice. It is a general fill-in-the-blank starting point and must be customized to the specific payer, claim, and clinical facts. Submitting an appeal does not guarantee a reversal of the denial or any particular outcome.