OA-23OA group · Coordination of benefits

OA-23 denial code: adjusted for the prior payer's adjudication

OA-23 is the same calculation as its CO twin with a group code that leaves the liability question deliberately open.

OA-23 reflects the prior payer's adjudication on a secondary claim, using the Other Adjustment group. Unlike CO, the OA group does not itself assign the amount to the provider as a write-off, and unlike PR it does not assign it to the patient.

What OA-23 means

Group codes carry financial meaning: CO is a contractual write-off, PR is patient responsibility, and OA is neither — an adjustment the code set does not classify. That ambiguity matters at posting time, because an OA amount handled as a write-off may forfeit a balance that belonged elsewhere, and one billed to a patient may be billed wrongly. The remittance's other lines usually resolve where the amount actually lands.

Why OA-23 fires

  • The secondary is coordinating against the primary's adjudication.
  • An adjustment does not fit the contractual or patient-responsibility categories.
  • The payer's mapping assigns coordination amounts to the Other Adjustment group by default.

Is OA-23 worth appealing?

Sometimes worth appealing

Establish where the amount belongs before writing it off. OA is the group code that says the payer has not told you, and posting it as a write-off by default loses money quietly.

How to resolve or appeal OA-23

  1. 1

    Read the whole remittance line

    Other adjustments on the same line usually establish whether a balance remains and to whom.

  2. 2

    Ask the payer to classify it

    Where it genuinely matters, ask in writing whether the amount is contractual or patient responsibility.

OA-23 — frequently asked

Can I bill the patient for an OA amount?
Not on the strength of the group code alone. OA does not assign responsibility, and billing a patient for an unclassified adjustment is a compliance risk as well as a service one.
Why do payers use OA here?
Often as a mapping default rather than a deliberate choice, which is exactly why the amount deserves a second look before it is posted.

Related guides

CO-23 · Coordination of benefitsOA-22 · Coordination of benefitsCO-129 · Administrative

Sources

Reason-code meanings are paraphrased from the X12 Claim Adjustment Reason Code list for plain-language reference; they are not reproduced verbatim. This is general information, not legal, coding, or medical advice — always confirm against the payer's remittance and policy.

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