OA-23 OA · Other Adjustment

OA-23 Denial Code: Reconciliation of the prior payer's payments and adjustments

An informational secondary-claim adjustment showing how the primary payer already adjudicated the claim. Not a denial - it reconciles the secondary payer's math with the primary's payment.

Group code
OA - Other Adjustment
Code type
CARC
Billable to patient?
No - informational COB adjustment
Appealable?
Not applicable - informational
Category
Coordination of Benefits
Common pairing
MA04
On a remittanceCAS*OA*23*125.00On a paper EOB it shows as OA-23.

What OA-23 means

OA-23 appears on secondary (coordination-of-benefits) remittances. It represents the amount the primary payer already paid or adjusted so the secondary payer's calculation reconciles. It is informational, not a denial - normally no action is needed beyond standard COB posting. If it looks wrong, verify the primary EOB was transmitted correctly.

Common causes

  • The claim was processed as secondary and reflects the primary payer's payment and adjustments.
  • Coordination of benefits between two payers.
  • A Medicare crossover claim sent to a secondary payer.

How to fix it

  • Post the secondary remittance normally - OA-23 is informational.
  • Confirm the primary EOB and payment were transmitted accurately if the balance looks off.
  • If the secondary underpaid based on wrong primary data, resubmit with the correct primary EOB.

How to prevent it

  • Ensure accurate COB order and primary EOB attachment on secondary claims.
  • Reconcile primary vs secondary payments during posting.
  • Keep coordination-of-benefits records current with payers.
Not applicable - informationalOA-23 is an informational coordination-of-benefits adjustment, not a denial. There is normally nothing to appeal; verify the primary payer's data only if the secondary calculation looks wrong.

Plain-English explanation authored by Medmio. The OA-23 code meaning reflects the standard CARC/RARC set maintained by X12 and CMS; Medmio does not reproduce X12's official descriptor text verbatim. Codes change up to three times per year — verify active status against the latest X12/CMS release. For official Medicare remittance-code guidance, see CMS. Educational guidance only, provided as-is with no guarantee of accuracy or outcome — not a substitute for professional billing, coding, or legal advice.
Last reviewed: May 2026

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