Denial code CO-22: Care may be covered by another payer
The payer believes another plan is primary and wants that plan to adjudicate first.
This care may be covered by another payer per coordination of benefits.
What CO-22 actually means
CO-22 means the payer’s coordination-of-benefits record shows other coverage it considers primary — another commercial plan, Medicare, workers’ compensation, or auto liability. It is not a coverage denial; it is a sequencing instruction. Frequently the COB record is simply stale, reflecting a plan the patient no longer has, and the fix belongs to the patient rather than to the claim.
Why this denial happens
- The patient has genuine dual coverage and the claim went to the secondary first.
- The payer’s COB record is out of date — an old employer plan or a terminated spouse’s policy is still listed as primary.
- The services are related to an accident or work injury that another carrier owns.
- Medicare Secondary Payer rules apply and were not accounted for.
How to resolve a CO-22 denial
- Determine the correct order of benefits before resubmitting anything.
- If another plan is genuinely primary, bill that plan and then submit here as secondary with the primary’s remittance.
- If the COB record is stale, the patient must contact the payer to update it — you cannot correct it from your side.
- For accident-related care, bill the liability or workers’ compensation carrier.
How to prevent it
- Ask about other coverage at every registration, not only at the first visit.
- Capture accident and injury indicators at intake so liability claims are routed correctly from the start.
Frequently asked
What does denial code CO-22 mean?
The payer believes another plan is primary and wants that plan to adjudicate first. The X12 description reads: "This care may be covered by another payer per coordination of benefits."
How do I fix a CO-22 denial?
Determine the correct order of benefits before resubmitting anything. If another plan is genuinely primary, bill that plan and then submit here as secondary with the primary’s remittance. If the COB record is stale, the patient must contact the payer to update it — you cannot correct it from your side. For accident-related care, bill the liability or workers’ compensation carrier.
Can CO-22 be billed to the patient?
Generally no. The recommended path for this code is "route to the correct payer" — check your payer agreement before transferring any balance to the patient.
Related denial codes
Related billing terms
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General revenue-cycle guidance, not legal, coding, or payer-specific advice. Claim adjustment reason codes are maintained by X12 and are revised periodically; payer policy and your provider agreement govern in any specific case. Always read the remark codes transmitted with the denial — they frequently carry the detail this code does not.