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N23 Remark Code: Patient Liability May Change (COB)

N23 is an informational alert that patient liability may be affected by coordination of benefits with other carriers and/or maximum benefit provisions. The patient's final balance may differ once other coverage or plan limits are applied.

Quick facts

Code
N23 (RARC N23)
Status
Active In use since January 1, 2000; last modified April 1, 2007.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • PR (Patient Responsibility): The patient responsibility shown may still change after another carrier processes the claim or a benefit maximum is applied.
  • OA (Other Adjustment): Adjustments tied to prior payer adjudication are reported for coordination purposes, not as a provider write-off.
Official description
Alert: Patient liability may be affected due to coordination of benefits with other carriers and/or maximum benefit provisions.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N23 means

N23 does not change anything on the claim by itself. It warns that the patient’s share shown on this remittance could be different in the end, for two possible reasons: another insurer may still pay part of the balance through coordination of benefits, or a plan maximum may limit what this payer covers.

It often appears with CARC 23 on secondary claims, or with CARC 119 when a benefit limit is involved.

What to do

  1. Check for other coverage. If the patient has another plan that has not been billed, send the claim with this remittance.
  2. Hold or adjust the patient statement until other carriers finish processing, so you do not bill the patient for amounts another plan will cover.
  3. Look at benefit maximums. If a limit was reached, explain to the patient why more of the charge falls to them.
  4. Recalculate the balance once all payers have processed.

Coordination problems are a frequent source of billing confusion; see the COB root-cause guide.

Codes that may appear with N23

  • OA-23 (The impact of prior payer(s) adjudication including payments and/or adjustments. (Use only with Group Code OA)): Reports the impact of a prior payer's adjudication on this claim.
  • PR-119 (Benefit maximum for this time period or occurrence has been reached.): A benefit maximum for the period or occurrence has been reached.
  • PR-2 (Coinsurance Amount): Coinsurance that could be reduced or covered by another carrier.
  • N16 (Family/member Out-of-Pocket maximum has been met.): The out-of-pocket maximum was met and payment moved to a higher percentage.
  • N7 (Alert: Processing of this claim/service has included consideration under Major Medical provisions.): Alert that the claim was processed under major medical provisions.
  • N536 (We are not changing the prior payer's determination of patient responsibility, which you may collect, as this service is not covered by us.): The payer leaves the prior payer's patient responsibility unchanged because it does not cover the service.

N23 FAQ

Should I bill the patient right away?

If the patient has other coverage that has not processed yet, it is usually better to bill that carrier first. The patient's balance may drop after the other plan pays.

Is N23 a denial?

No. It is a caution that the patient responsibility on this remittance may not be final.

What benefit maximums could be involved?

It could be an annual or lifetime dollar limit, a visit limit, or another maximum in the plan. The paired CARC usually indicates which applies.