How do I resolve a CO-B12 denial?

Review the full denial on the 835 ERA for CARC B12: "Services not documented in patient's medical records." Pull the original claim and all supporting documentation for the date of service. See full resolution steps at tryarceum.com.

Can I appeal a CO-B12 denial?

Yes. Most CO-B12 denials can be appealed within 60-180 days depending on payer. This is appealable if documentation exists but was not initially submitted or if additional records can demonstrate the service was performed. Use our free tool to generate an appeal letter.

CARC Code

B12

🟡 Soft Denial

Services Not Documented in Records

The insurance company denied payment because the provider's medical records do not contain documentation of the services that were billed. The payer could not verify that the service actually occurred based on the clinical notes submitted.

missing info

Resolution: 85%Easy difficulty3-7 days avg

How to resolve this denial

Which payer denied this claim?

Review and resolve CARC B12: Services not documented in patient's medical records.

1
Review the full denial on the 835 ERA for CARC B12: "Services not documented in patient's medical records."
2
Pull the original claim and all supporting documentation for the date of service.
3
Identify the specific data element, policy requirement, or documentation gap that triggered this adjustment.
4
Correct the identified issue — update claim data, gather missing documentation, or verify coverage details.
5
Resubmit as a corrected claim (frequency type 7) or file a written appeal with supporting documentation.
6
Follow up with the payer within 10-15 business days to confirm adjudication.

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▶✓ Pre-action checklist — verify before contacting the payer

Review the full remittance advice (ERA/EOB) for additional RARC codes that explain the denial.
Verify the claim was submitted with correct patient eligibility and benefit information.
Check if this denial applies to a specific line item or the entire claim.

▶More about CO-B12 — stats, related codes, appeal template

85%

Recovery Rate

3-7 days

Avg. Resolution

Easy

Difficulty

Rare

Frequency

Payer-Specific Notes

How major payers handle CARC B12 by specialty.

General

Confirm payer-specific policy for CARC B12 and submit corrected claim or appeal as appropriate.

Appeal Letter Template

Generic appeal template for CARC B12 denials.

Dear [Payer Name] Appeals Department, We are writing to appeal the denial of claim [CLAIM #] for patient [PATIENT NAME] (Member ID: [ID]) for services rendered on [DATE OF SERVICE]. The claim was denied with CARC B12: "Services not documented in patient's medical records." We believe this denial is in error for the following reasons: [INSERT CLINICAL/ADMINISTRATIVE JUSTIFICATION] We respectfully request reconsideration and payment of this claim. Sincerely, [Provider Name / Billing Contact]

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