CO-167: Diagnosis Not Covered by This Payer

CO (Contractual Obligation)

What is CO-167?

CO-167 is a Contractual Obligation code indicating the diagnosis submitted with the claim is not covered under the patient's benefit plan or the payer's coverage policies. This differs from CO-11 (medical necessity) in that CO-167 means the diagnosis itself is excluded, not that it fails to support the procedure.

Why Does CO-167 Occur?

  1. Diagnosis excluded from plan coverage. Certain ICD-10 codes are explicitly excluded in the patient's benefit plan (e.g., cosmetic conditions, self-inflicted injuries in some plans).
  2. Workers compensation or auto insurance should be primary. The diagnosis code indicates an injury that should be covered by WC or auto liability, not the health plan.
  3. Pre-existing condition limitation (rare, mostly grandfathered plans). The diagnosis relates to a pre-existing condition that the plan excludes.

How to Fix CO-167 Denials

  1. Review the EOB to identify why the diagnosis is not covered. The RARC code will specify the exclusion reason.
  2. If the diagnosis is truly excluded from the plan, check for an alternative ICD-10 code that is more clinically accurate and covered.
  3. If the denial is because another payer should be primary (WC, auto), redirect the claim to the correct payer.
  4. Appeal with clinical documentation if the payer's exclusion is incorrect or if the diagnosis falls within a coverage exception.

CO-167 by Payer

Payer Common RARC Appeal Deadline Notes
UnitedHealthcare N/A 60 days from remittance Check UHC plan documents for diagnosis-specific exclusions.
Anthem N/A 365 days from denial notice Anthem's coverage varies by state. Verify the exclusion against your region.
Aetna N/A 180 days from denial Review Aetna's excluded diagnosis list for the patient's plan.
Cigna N/A 180 days from denial Contact Cigna to confirm the diagnosis exclusion is correct for the plan.
Medicare N/A 120 days (redetermination at MAC) Medicare rarely excludes diagnoses. Verify the claim was not miscoded.

Related CARC Codes

If you are seeing CO-167, check these related codes: CO-11 (medical necessity), CO-50 (non-covered service), CO-15 (workers compensation).

Common Questions About CO-167

What is the difference between CO-167 and CO-11?

CO-167 means the diagnosis itself is not covered by the plan. CO-11 means the diagnosis does not support the medical necessity of the procedure billed. CO-167 is a coverage exclusion; CO-11 is a medical necessity failure.

Can the patient be billed for a CO-167 denial?

Possibly. If the patient was informed before the service that the diagnosis may not be covered and signed a waiver (ABN for Medicare), the balance may be transferred to the patient.

Altair catches CO-167 denials before submission with coverage eligibility checking. See how pre-submit claim scoring works.

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This reference is for informational purposes. Always verify against current payer policies and CMS guidelines. Last updated: 2026-03-09.