Quick Explanation
Denial code CO-22 indicates that the payer believes another insurance plan is responsible for payment due to Coordination of Benefits (COB) rules, meaning the claim was likely submitted to the wrong payer or the payer order is unclear. This code is distinct from other denials (such as CO-50 for lack of medical necessity or CO-16 for missing information) because it specifically relates to multi-insurance scenarios and payer liability, not clinical or administrative completeness.
Common Causes for 22
Denials with code 22 typically happen for the following specific reasons:
- Claim submitted to the secondary insurer before the primary insurer has processed it.
- Incorrect or outdated insurance information on file (e.g., patient changed jobs or dropped coverage).
- Failure to identify and document the correct primary and secondary payer order per COB rules.
- Missing or illegible Explanation of Benefits (EOB) from the primary payer when submitting to secondary.
- Conflicting or overlapping coverage dates between two active insurance plans.
How to Prevent 22 Denials
To avoid receiving this denial in the future, implement these specific checks:
- Verify and document the correct primary and secondary insurance order at every patient encounter.
- Use payer portals or eligibility verification tools to confirm active coverage and COB status before claim submission.
- Update patient insurance information in the billing system whenever changes are reported.
- Ensure claims are always submitted to the primary payer first, and only submit to secondary with the primary EOB.
- Automate COB checks and flag claims with dual coverage for manual review before submission.
Appeal Letter Template for 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: 22 - Coordination of Benefits (COB)
Dear Appeals Department,
I am writing to appeal the denial of the above-referenced claim, which was denied with code 22: "Coordination of Benefits (COB)".
This claim should be reconsidered for payment as the Coordination of Benefits (COB) process has been properly followed, and the billed payer is confirmed as the primary insurer per the patient’s current coverage and policy enrollment dates. Supporting documentation, including the patient’s insurance cards and eligibility verification, confirms that no other active insurance plan is responsible for primary payment. The service was rendered within the coverage period, and all required COB information was submitted with the claim. Therefore, the denial based on CO-22 is not applicable, and the payer is contractually obligated to process and adjudicate this claim as the primary insurer.
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]
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