This care may be covered by another payer per coordination of benefits (Updated for 2026)

Common Causes for CO-22

Denials with code CO-22 typically happen for the following specific reasons:

• The patient has multiple active health insurance policies, and the primary policy was not billed first.
• The claim was submitted to a secondary payer without the primary insurance's Explanation of Benefits (EOB) or payment details attached.
• The medical condition is related to an auto accident or work-related injury, meaning auto liability or workers' compensation is the primary payer.
• The patient has not completed or updated their annual coordination of benefits questionnaire with their insurance company, causing a claim hold.

How to Prevent CO-22 Denials

To avoid receiving this denial in the future, implement these specific checks:

• Verify patient eligibility and active insurance coverage prior to every visit, asking specifically if they have secondary or other primary coverage.
• Establish the correct order of benefits using standard NAIC rules (such as the 'birthday rule' for dependents or active vs. inactive employee status) during intake.
• Always submit secondary claims with the primary payer's Explanation of Benefits (EOB) or Electronic Remittance Advice (ERA) to show the primary adjudication.
• Advise patients immediately if their claims are held for COB, directing them to contact their insurance carrier's coordination of benefits department to update their files.

Appeal Letter Template for CO-22

If you believe this claim was denied incorrectly, you can use the following template to submit an appeal.

[Your Practice Header]
[Date]

[Payer Name]
[Appeals Department Address]

RE: Appeal for Claim [Claim Number]
Patient: [Patient Name]
ID: [Patient ID]
Date of Service: [Date]
Denial Code: CO-22 - This care may be covered by another payer per coordination of benefits

Dear Appeals Department,

I am writing to appeal the denial of the above-referenced claim, which was denied with code CO-22: "This care may be covered by another payer per coordination of benefits".

We are appealing the denial under code CO-22 regarding coordination of benefits (COB). Pursuant to NAIC guidelines and standard industry coordination of benefits rules, we have verified that [Payer Name] is the appropriate payer for these services. Attached, please find the patient's completed COB documentation, along with the primary payer's Explanation of Benefits (EOB) reflecting their adjudication, deductible, and co-insurance details. Because all secondary billing requirements have been satisfied, we respectfully request that you review the attached documentation and process this claim for payment in accordance with your coordination of benefits policies.

Attached please find:
1. A copy of the original claim.
2. The relevant medical records supporting the service.
3. [Any other supporting documents].

We respectfully request that you reprocess this claim for payment.

Sincerely,

[Your Name]
[Title]
[Practice Name]