CO-55 Denial Code Explained

CO-55 is a medical billing denial code that indicates the billed procedure or treatment requires additional review before reimbursement can be approved.

What Does CO-55 Mean?

The CO-55 denial code means the insurance payer determined the claim requires further review, supporting documentation, or policy evaluation before payment can be issued.

This denial is often related to medical necessity reviews or payer policy requirements.

Common Reasons for CO-55

• Additional documentation required

• Medical necessity review

• Incomplete clinical records

• Payer policy evaluation

• Authorization concerns

• Coding inconsistencies

How To Fix CO-55

Review the payer request carefully and submit all required documentation supporting the billed service. Providers may need to provide physician notes, treatment records, or authorization approvals before resubmitting the claim.

Related Denial Codes

You may also encounter:

• CO-167 — Additional information required

• CO-151 — Documentation does not support billed service

• CO-236 — Service does not meet payer coverage criteria

• CO-50 — Service not medically necessary

Quick Summary

CO-55 indicates the payer requires additional review or documentation before reimbursement can be approved. Most denials are related to documentation or policy review requirements.

Medical billing denial codes, insurance prefixes, and claim guidance in one searchable resource hub.

© 2026. All rights reserved.

Quick Links

Denial Codes

BCBS Prefixes

Articles

Resources

About ClariMed

Terms and Conditions

Privacy Policy