CO-31 Denial Code Explained

CO-31 is a medical billing denial code that indicates the patient cannot be identified as the insured individual. This denial commonly occurs when patient information is incorrect or incomplete during claim submission.

What Does CO-31 Mean?

The CO-31 denial code means the insurance payer could not match the submitted patient information with an active insurance policy or insured member record.

This denial is often related to eligibility verification issues or incorrect demographic information.

Common Reasons for CO-31

• Incorrect patient name

• Invalid member ID number

• Incomplete insurance information

• Incorrect date of birth

• Eligibility verification errors

• Outdated patient records

How To Fix CO-31

Verify the patient’s demographic and insurance information before resubmitting the claim. Confirm the member ID number, policy details, and insured information directly with the payer or patient.

Correcting patient records can help reduce future eligibility denials.

Related Denial Codes

You may also encounter:

• CO-9 — Patient not eligible for benefits

• CO-16 — Missing or incomplete claim information

• CO-22 — Coordination of benefits issue

• CO-170 — Coverage terminated before service date

Quick Summary

CO-31 indicates the payer could not identify the insured patient based on the submitted claim information. Most denials are related to incorrect demographic or insurance details.

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