CO 167 Denial Code: Diagnosis Coverage and Next Steps

What Does CO 167 Mean?

CO 167 means the insurer considers the submitted diagnosis or diagnoses non-covered for the service. It does not, by itself, establish that the diagnosis code is invalid.

CO means Contractual Obligation and assigns the adjusted amount to the provider. 167 is the Claim Adjustment Reason Code (CARC) that identifies the diagnosis coverage issue. The X12 code list provides the official definition.

The insurer sends the code after claim review, alongside its payment explanation. CARCs have standardized definitions maintained by the Claim Adjustment Status and Reason Code Maintenance Committee; the applicable insurer policy determines coverage.

The Test’s Purpose Matters

Screening and diagnostic testing can involve different coverage requirements. Screening looks for a condition before symptoms appear; diagnostic testing investigates a clinical concern.

For example, Medicare’s screening prostate-specific antigen (PSA) instructions identify CARC 167 for claims that lack the required screening diagnosis code. The test’s purpose and the diagnosis reported therefore need to agree.

This does not mean staff should relabel a diagnostic test as screening, or the reverse, to obtain payment. The clinician’s records must establish why the test occurred.

Trace the Diagnosis From the Record to the Claim

Start with the affected test and the diagnosis the insurer received. Read any accompanying remark codes and policy references to identify the specific coverage concern.

Then compare three things:

• The clinical record: What condition, symptom, or screening purpose did the clinician document?
• The order: Does it communicate that reason clearly?
• The submitted claim: Does the diagnosis match the records and support the correct service line?

If those details disagree, ask the clinician to clarify the documentation and correct any supported claim error through the insurer’s required process.

If they agree, review the policy effective on the service date. When the records support coverage, follow the insurer’s reconsideration or appeal instructions. When they do not, another submission with the same information is unlikely to resolve the issue.

Do not choose a diagnosis simply because it appears on a covered-code list. Any correction must reflect the patient’s documented circumstances.

CO assigns responsibility to the provider, so do not automatically move the denied amount to the patient. Check the applicable liability rules before any patient charge.

How Is CO 167 Different From CO 50?

CO 167 points specifically to diagnosis coverage. The CO 50 denial code identifies a broader medical necessity decision. The insurer’s explanation and policy determine what evidence each case needs.

Earlier review can help prevent avoidable mismatches. The Docus AI Compliance Agent can flag potential conflicts between ordered tests and selected diagnoses for staff review. Providers remain responsible for diagnosis selection, and the insurer determines payment.