CO-167: This (these) diagnosis(es) is (are) not covered.
The specific diagnosis code or codes billed are excluded from coverage for this service or plan, distinct from a modifier or procedure issue. The payer's policy does not recognize this diagnosis as payable for the billed service.
What the group code means
- CO
- Contractual Obligation. The provider is responsible and the amount cannot be billed to the patient.
This CARC is reported under more than one group code depending on the payer and the circumstances: PR, CO.
Why it fires
- The diagnosis code is on the payer's non-covered or excluded list for this benefit
- The ICD-10 code does not match any diagnosis accepted under the relevant LCD, NCD, or medical policy
- A more specific or different diagnosis code should have been used based on the documentation
Corrective actions, ranked
- 1
Check the LCD or medical policy
Compare the billed diagnosis against the payer's covered diagnosis list for this procedure.
- 2
Query for a more accurate diagnosis
If documentation supports a covered, more specific ICD-10 code, obtain clarification from the ordering provider and rebill.
- 3
Notify the patient in advance next time
For known non-covered diagnoses, get an ABN or equivalent waiver before the service so the patient can be billed appropriately.
Is it worth appealing
Appeal with clinical documentation when the correct, more specific diagnosis is actually covered and was simply coded imprecisely.
Related remark codes
Retrieved 2026-07-18.
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DenialPath provides billing and administrative guidance based on published CMS and X12 sources. It is not medical advice, not a coverage determination, and not a guarantee of payment. NCCI and MUE edits are republished quarterly and payer policies vary by contract. Always confirm against the payer's own current policy before submitting or appealing.