CO-20 Denial Code Explained

CO-20 is a medical billing denial code that indicates the claim cannot be processed because the patient is covered by another insurance plan that should be billed first. This denial commonly occurs when coordination of benefits information is missing, incorrect, or outdated.

What Does CO-20 Mean?

The CO-20 denial code means the insurance payer believes another payer is primarily responsible for the claim.

This denial is often related to coordination of benefits issues, multiple insurance policies, or incorrect payer sequencing.

Common Reasons for CO-20

• Another insurance payer is primary

• Coordination of benefits information is incorrect

• Secondary insurance billed before primary insurance

• Patient coverage information is outdated

• Medicare Secondary Payer (MSP) rules apply

• Incorrect payer order on the claim

How To Fix CO-20

Review the patient's insurance coverage and verify which payer is primary and which payer is secondary. Update any incorrect coordination of benefits information and submit the claim to the appropriate payer.

If the claim has already been processed by the primary payer, include the primary payer's explanation of benefits when billing the secondary insurance carrier.

If the claim involves office visit services, review the reported CPT codes to ensure the claim was billed correctly. Additional coding resources can be found on CPTCodeGuide.com.

Frequently Asked Questions

What does CO-20 mean?

CO-20 means another insurance payer is responsible for processing the claim before the current payer.

Is CO-20 a coordination of benefits denial?

Yes. CO-20 is commonly associated with coordination of benefits and payer sequencing issues.

Can CO-20 be appealed?

Most CO-20 denials are resolved by correcting insurance information and billing the appropriate payer rather than filing an appeal.

What should I check first after receiving CO-20?

Verify the patient's active insurance coverage and confirm the correct primary and secondary payer order.

Is CO-20 common for patients with multiple insurance plans?

Yes. Patients covered by multiple insurance policies frequently receive CO-20 denials when payer information is incorrect.

Related Denial Codes

You may also encounter:

• CO-18 — Duplicate claim or service

• CO-22 — Coordination of benefits issue

• CO-26 — Expenses incurred prior to coverage

• CO-27 — Expenses incurred after coverage terminated

• CO-109 — Claim not covered by this payer

Quick Summary

CO-20 indicates another insurance payer is responsible for processing the claim first. Most denials are caused by coordination of benefits issues, incorrect payer sequencing, or outdated insurance information.