Another payer may be primary
The payer's records show the patient has other insurance that should pay first (coordination of benefits).
CO = Contractual Obligation. The provider owes the difference. The patient cannot be billed for this amount. The same reason code can appear with a different group code; the group decides who may be billed.
Usual causes
- The patient has two plans and you billed the secondary first.
- Outdated other-insurance information in the payer's file (a plan the patient no longer has).
- Medicare patient with an employer group plan that is primary.
The fix
Verify coverage with the patient. Bill the primary payer, then send this payer the claim with the primary remittance. If the other coverage ended, the patient must call the payer to update coordination of benefits; then ask for reprocessing.
Appeal or corrected claim?
Not an appeal. Resubmit as a secondary claim with the primary EOB, or have the patient update their coordination of benefits.
Deadline to watch
Timely filing for the primary payer runs from the date of service. Most payers restart the secondary clock from the primary remittance date, but check the contract.
Exact limits are in your payer contract or provider manual. When in doubt, send the correction or appeal this week.
Often seen together
The payer believes another plan is primary and needs its payment information. Bill the primary first, or have the patient update coordination of benefits.
CO-22 in short
What does CO-22 mean?
The payer's records show the patient has other insurance that should pay first (coordination of benefits). The official X12 text reads: "This care may be covered by another payer per coordination of benefits."
What usually causes a CO-22 denial?
The patient has two plans and you billed the secondary first. Outdated other-insurance information in the payer's file (a plan the patient no longer has). Medicare patient with an employer group plan that is primary.
How do I fix CO-22?
Verify coverage with the patient. Bill the primary payer, then send this payer the claim with the primary remittance. If the other coverage ended, the patient must call the payer to update coordination of benefits; then ask for reprocessing.
Should I appeal CO-22 or send a corrected claim?
Corrected claim. Not an appeal. Resubmit as a secondary claim with the primary EOB, or have the patient update their coordination of benefits.
What deadline applies to CO-22?
Timely filing for the primary payer runs from the date of service. Most payers restart the secondary clock from the primary remittance date, but check the contract.