EOB denial code · OA group
OA-23: Coordination of Benefits (Other Payer) — Meaning
OA-23 is an 'other adjustment' showing coordination of benefits: the plan reduced or denied payment because another insurance should process the claim first (or already did). It's the OA-group cousin of CO-22 — a payer-ordering matter, not a service you owe. Give both insurers' information to the provider so the claim is billed to the correct primary, then the secondary plan processes the remainder.
What “OA-23” means on your EOB
Payment adjusted because this payer is secondary to another payer.
Who pays? OA — Other Adjustment
OA (other adjustment) — the plan is not paying because another plan is primary. Your responsibility only appears AFTER the primary plan pays; run the claim through both before paying anything.
What to do next: Give the provider both insurance ID cards and ask them to file with the primary plan FIRST, then send the primary's EOB to the secondary. If you only have one plan, call the payer's coordination-of-benefits line and ask them to remove any stale policy in their records. The secondary plan should pay its share once it has the primary's EOB.
Why this denial happens
- Two active plans and the claim went to the secondary plan first.
- An outdated policy record shows a plan that's no longer active.
- The provider only submitted to one plan.
- The secondary plan processed without the primary's EOB on file.
What to do now
- Identify which plan is primary (birthday rule for dependents; your own employer plan usually first).
- Confirm the provider has BOTH insurance cards and filed with the primary first.
- Once the primary pays, send its EOB to the secondary plan.
- If you have only one plan and still see OA-23, call the COB department and update your policy records.
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