CO-22 Denial Code: Care May Be Covered by Another Payer (Coordination of Benefits)

What does denial code CO-22 mean?

CO-22 means "this care may be covered by another payer per coordination of benefits." The payer you billed checked its COB file, found evidence of other coverage, and is refusing to adjudicate as primary until the payer order is proven. It is not a coverage or coding denial; it is a "you asked the wrong insurance first, maybe" denial.

Example: a patient has an employer PPO and is also on a spouse's plan. You bill the spouse's plan for a $210.00 office visit. The ERA reads: billed $210.00, allowed $0.00, CO-22 $210.00, paid $0.00, remark N4 or a COB questionnaire notice. The spouse's plan believes the patient's own employer plan is primary, which under standard COB rules it is.

Why did the claim get a CO-22?

• Genuine dual coverage billed in the wrong order: employer plan vs. spouse's plan, Medicare vs. employer group coverage, auto or workers' comp liability ahead of health insurance.
• Stale COB data. The payer's file shows old coverage the patient dropped years ago; until the member confirms it ended, everything denies CO-22.
• Unanswered COB questionnaire. Many plans mail members an annual other-coverage survey and pend or deny claims until it comes back.
• Registration miss. The front desk keyed only one insurance when the patient actually has two, so the secondary was billed as primary.

How do you fix and resubmit a CO-22 denial?

1. Ask the patient directly about all current coverage, including a spouse's plan, Medicare, Medicaid, or an open accident claim.
2. Determine the true primary using COB rules (subscriber's own plan first; birthday rule for dependent children; Medicare Secondary Payer rules for working aged).
3. Have the patient call the denying payer to update COB or complete the questionnaire. Give them the member services number and say exactly what to confirm.
4. Bill the true primary. When its EOB arrives, submit to the secondary with the primary payment data in the claim (or attach the EOB on paper).
5. If the "other coverage" does not exist, rebill after the patient confirms COB; the claim should then process normally.

How do you prevent CO-22 denials?

Ask about other coverage at every check-in, not just the first visit, and store the answer with a date. Verify coordination of benefits during eligibility checks for new patients, patients over 65, dependents, and anyone with an injury-related visit. Flag accounts with dual coverage in your PM system so claims release in the right order automatically, and watch the timely filing limits on the true primary whenever COB is unresolved.

Can you appeal a CO-22 denial?

Rarely worth it, because CO-22 usually is not a judgment call; it is a data problem that COB confirmation solves. Appeal only when the payer keeps denying after the member has confirmed there is no other coverage, and attach the member's confirmation reference number. If a resolved COB claim is now bumping against filing limits, use the appeal deadline calculator and submit with proof of the original timely submission and the COB delay.