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OA-22 Denial Code: Another Payer May Be Primary (COB)

OA-22 means the payer believes another insurance may be primary for this patient under coordination of benefits, so it won't pay until the other payer processes the claim or the COB record is corrected. Bill the primary first, or update the coverage order with the patient and payer.

Quick facts

Code
OA-22 (CARC 22)
Status
Active In use since January 1, 1995; last modified September 30, 2007.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • OA (Other Adjustment): The common group: the amount isn't assigned to provider or patient yet because coordination of benefits must be resolved.
  • CO (Contractual Obligation): Some payers use CO. Don't bill the patient; resolve which payer is primary and resubmit.
  • PR (Patient Responsibility): Used when the payer holds the patient responsible, often because the member hasn't returned a COB questionnaire. The patient should update their coverage with the plan.
Official description
This care may be covered by another payer per coordination of benefits.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What OA-22 means

CARC 22 says this care may be covered by another payer per coordination of benefits. When a patient has more than one plan, only one can be primary. The payer that sends OA-22 believes it’s secondary (or can’t tell) and wants the claim to go through the other payer first.

The word “may” matters. The payer isn’t always certain. Its records might show another active policy, a spouse’s employer coverage, Medicare entitlement, or an unanswered COB questionnaire. Sometimes the information is outdated: the other coverage ended months ago.

For a deeper look at COB root causes, see eligibility and COB denials.

Common causes

  • Patient has another active plan that is primary under coordination rules, such as their own employer plan versus a spouse’s.
  • Dependent children covered by both parents, where the birthday rule or a court order decides primary.
  • Medicare Secondary Payer situations, where an employer group health plan pays before Medicare.
  • Outdated COB record at the payer showing coverage that has ended.
  • Unanswered COB questionnaire, which some plans require periodically before they pay.
  • Secondary claim sent without primary payment data in the COB loops or boxes 9 to 9d and 11d (MA04).

How to fix it

  1. Ask the patient about every current plan, including spouse or parent coverage, Medicare, Medicaid, and TRICARE.
  2. Verify each plan’s eligibility and what each payer shows as primary.
  3. If another plan is primary, bill it first, then send the secondary claim with the primary’s paid amount and adjustments.
  4. If this payer should be primary, have the patient call the plan to update the COB record or complete the questionnaire, then ask for reprocessing.
  5. Correct boxes 9 to 9d and 11d (or the 837 other-subscriber loops) and resubmit if the claim itself was wrong.
  6. Hold patient billing until COB is resolved, unless the payer assigns the amount to the patient.

How to prevent it

  • Ask about other coverage at every visit, not just at intake.
  • Run eligibility for every plan the patient reports and record the coverage order.
  • Remind patients to answer COB questionnaires from their plans.
  • Send complete COB data on secondary claims. A Claims Validator check can confirm other-payer fields are filled in before submission.

Specialty notes

Pediatric practices see OA-22 often because children are frequently covered by both parents. Practices with many Medicare patients who are still working, or whose spouse is working, should screen for Medicare Secondary Payer situations.

Remark codes that may appear with OA-22

  • MA04 (Secondary payment cannot be considered without the identity of or payment information from the primary payer.): Secondary payment can't be considered without the primary payer's identity or payment information.
  • N479 (Missing Explanation of Benefits (Coordination of Benefits or Medicare Secondary Payer).): The primary payer's explanation of benefits is missing.
  • MA92 (Missing plan information for other insurance.): Plan information for the other insurance is missing.
  • N598 (Health care policy coverage is primary.): Another health care policy is primary.
  • OA-23 (The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)): The impact of the prior payer's adjudication, seen once COB is working correctly.
  • CO-109 (Claim/service not covered by this payer/contractor.): Not covered by this payer at all; send the claim to the correct payer.
  • OA-19 / CO-20 / CO-21 (Workers' comp, liability, and no-fault carriers.): Specific other payers for injuries, as opposed to another health plan.
  • OA-136 (Failure to follow prior payer's coverage rules. (Use only with Group Code OA)): Failure to follow the prior payer's coverage rules.

OA-22 FAQ

What does OA-22 mean in simple terms?

The insurer thinks the patient has other coverage that should pay first. It wants the primary payer's EOB, or confirmation that it is actually primary, before it pays.

How do I fix an OA-22 denial?

Ask the patient about all current coverage, verify with each payer, and bill the correct primary first. Then bill the secondary with the primary's payment information. If the payer's COB record is wrong, the patient usually needs to call to update it.

What if the patient has no other insurance?

The patient should contact the plan to update its COB record or complete its questionnaire. Once the payer updates the record, ask it to reprocess the claim.

Who decides which plan is primary?

Standard coordination rules, such as the birthday rule for dependent children and active employment rules, along with Medicare Secondary Payer rules for Medicare patients. Payers apply these rules to the coverage they know about.