Official CARC description: “The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)” Here’s what it actually means, why it fires, and how to get the claim paid.
The standard secondary-claim math line: this payer's allowed amount is reduced by what the primary already handled. The most-searched version of the code — and the most misunderstood as a “denial”. It isn't one.
Liability group: OA = Other Adjustment — neither clearly provider nor patient liability — most often coordination-of-benefits math or duplicates. Usually informational; verify before writing anything off.
Also written: OA-23, OA23, “denial code 23”, “23 denial code” or “reason code 23” — same CARC, different ERA formatting.
Reason code 23 also appears under another group on the ERA. The number is the reason; the prefix decides who absorbs the money. This page covers OA 23 (Other Adjustment). If your ERA shows a different prefix, use the matching page:
Reconcile: primary paid + primary adjustments + this payer's action should equal billed
Zero secondary payment? Check for a non-duplication COB clause before assuming error
Wrong primary figures: corrected secondary claim
Post OA 23 amounts to the COB adjustment bucket, never to patient balance
Nothing to appeal in the code itself — audit the arithmetic and the COB method. Only methodology misapplication (attach both EOBs and the plan's COB provision) merits a dispute.
Fill in the denial facts — use placeholders, never real patient data (the letter keeps [PATIENT NAME]-style fields so you can merge real details privately). A payer-ready draft with an enclosure checklist comes back in ~20 seconds.
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The official CARC description for OA 23 is: “The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)” In practice: The standard secondary-claim math line: this payer's allowed amount is reduced by what the primary already handled. The most-searched version of the code — and the most misunderstood as a “denial”. It isn't one.
Denial code 23 under the OA group (Other Adjustment) means: The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA) The number is the reason; the OA prefix decides who is liable — neither clearly provider nor patient liability — most often coordination-of-benefits math or duplicates. Usually informational; verify before writing anything off.
Yes. OA 23, OA-23, OA23 and “denial code 23” are the same CARC — clearinghouses, payer portals and PM systems just print it differently. Only the group prefix (CO, PR, OA or PI) changes the meaning, because it changes who has to absorb the amount.
OA stands for Other Adjustment — neither clearly provider nor patient liability — most often coordination-of-benefits math or duplicates. Usually informational; verify before writing anything off.
Nothing to appeal in the code itself — audit the arithmetic and the COB method. Only methodology misapplication (attach both EOBs and the plan's COB provision) merits a dispute.
The number 23 is the same reason code in both — what changes is the liability group. CO 23 is Contractual Obligation. OA 23 is Other Adjustment, so neither clearly provider nor patient liability. Check the prefix on the ERA before you write anything off or bill the patient — a mis-grouped 23 is one of the more winnable appeals.