CARC 31 appeal letter template — Patient Cannot Be Identified As Insured

CARC 31 means the payer's records could not match the patient to an active insured member, often due to a data entry error, outdated member info, or incorrect payer routing. This template helps staff formally request reconsideration once identification details are confirmed or corrected.

When to appeal vs. correct & resubmit

Appeal with this template when you have verified that the patient was in fact an active insured member on the date(s) of service and can supply corrected or supporting identification details (e.g., correct Member ID, subscriber name, DOB, or group number). If the patient was genuinely not covered by this payer on the DOS, do not appeal — instead verify correct coverage, rebill the correct payer, or contact the patient for updated insurance information.

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]
Attn: Appeals Department
[Payer Address]

Re: Appeal of Claim Denial — CARC 31 (Patient Cannot Be Identified As Our Insured)
Patient Name: [Patient Name]
Member ID: [Member ID]
Claim #: [Claim #]
Date(s) of Service: [DOS]
Billed Provider: [Provider Name, NPI]
CPT/HCPCS: [CPT/HCPCS]

To Whom It May Concern:

This letter is a formal appeal of the above-referenced claim, which was denied under CARC 31: "Patient cannot be identified as our insured." We respectfully request that this denial be reconsidered based on the corrected and/or confirmed identification details provided below.

We have verified the following information to assist in matching the patient to the correct member record:
- Corrected/Confirmed Member ID: [Member ID]
- Patient Name as it appears on the insurance card: [Patient Name]
- Group Number (if applicable): [Group Number]
- Subscriber Name (if different from patient): [Subscriber Name]
- Date of Birth: [DOB]

Enclosed is a copy of the patient's insurance card and/or eligibility verification confirming active coverage with [Payer Name] on the date(s) of service listed above. We ask that you re-process this claim using the corrected information and issue a revised determination.

If additional information or documentation is needed to complete this identification, please contact our office at [Phone] or [Email], and we will respond promptly.

Thank you for your attention to this matter. We look forward to your reconsideration.

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

What to attach

• Copy of patient's insurance card (front and back)
• Eligibility verification/response showing active coverage on the DOS
• Original EOB/ERA showing the CARC 31 denial
• Corrected claim form (CMS-1500 or UB-04) with verified member/subscriber information
• Patient intake/registration form confirming demographic details

Frequently asked questions

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

This template is for informational and administrative purposes only and does not constitute legal, billing, or coding advice. It is not a guarantee of appeal success or claim payment. Always verify requirements with the specific payer and consult qualified billing/legal professionals as needed.