How do I resolve a CO-9 denial?

Pull the original claim and review the specific field flagged by the RARC code Compare claim data against the patient's insurance card and eligibility response See full resolution steps at tryarceum.com.

Can I appeal a CO-9 denial?

Yes. Most CO-9 denials can be appealed within 60-180 days depending on payer. This is appealable if the diagnosis is clinically appropriate and documentation supports the condition can occur at the patient's age despite typical age restrictions. Use our free tool to generate an appeal letter.

CARC Code

9

🟡 Soft Denial

Diagnosis Inconsistent with Patient Age

The claim was denied because the diagnosis code submitted does not match what is medically appropriate for the patient's age. For example, a pediatric condition was billed for an adult patient, or an age-related condition was coded for a child.

coding

Resolution: 82%Medium difficulty7-14 days avg

How to resolve this denial

Which payer denied this claim?

Correct the diagnosis code to match patient age

1
Pull the original claim and review the specific field flagged by the RARC code
2
Compare claim data against the patient's insurance card and eligibility response
3
Correct the identified field(s) in the practice management system
4
Resubmit the corrected claim via the payer portal or clearinghouse
5
Confirm receipt and track the corrected claim to adjudication

Resolve this denial →

▶✓ 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-9 — stats, related codes, appeal template

82%

Recovery Rate

7-14 days

Avg. Resolution

Medium

Difficulty

Occasional

Frequency

Payer-Specific Notes

How major payers handle CARC 9 by specialty.

Aetna

Aetna uses CO-9 when procedure/diagnosis combination fails edit. Check RARC for specific field.

Common 835 Combinations

CARC 9 most often appears with these Group Code + RARC combinations on 835 remittances.

COCO-9The payer denied the claim because a diagnosis code submitted is not clinicallyAppealable

Look up any combination →

Appeal Letter Template

Generic appeal template for CARC 9 denials.

We are submitting a formal appeal for claim [CLAIM_NUMBER] for patient [PATIENT_NAME], date of service [DOS]. This claim was denied/adjusted with CARC 9 indicating: "The diagnosis is inconsistent with the patient's age.." We have reviewed the claim and are providing the attached documentation to support reconsideration. [SUPPORTING_DOCUMENTATION]. Please reconsider payment per the terms of our contract.

Generate a personalized appeal letter →

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