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N857 Remark Code: Claim Reversed, Refund the Copay

N857 means the claim has been adjusted or reversed, and any copayment you collected from the member for it should be refunded. The payer's reprocessing changed the basis for the copay, so the member shouldn't keep paying it.

Quick facts

Code
N857 (RARC N857)
Status
Active In use since November 1, 2021.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): Amounts reversed under CO are provider liability. Don't transfer them to the patient.
  • PR (Patient Responsibility): The reversal removes the copay that was previously reported as patient responsibility.
Official description
This claim has been adjusted/reversed. Refund any collected copayment to the member.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N857 means

When a payer reverses or adjusts a claim it previously processed, the patient responsibility tied to the original claim changes too. N857 is the payer telling you directly that the copay collected for this claim is no longer supported and should go back to the member.

It usually appears on a reversal or adjustment remittance, which means it may show up weeks or months after the visit, long after the copay was posted.

Common causes

  • Retroactive eligibility change, for example coverage terminated or moved to another plan.
  • Coordination of benefits correction, with another payer now primary.
  • Corrected or replacement claim that reprocessed the service differently.
  • Program rules that bar copays for certain members or services, applied on review.

What to do

  1. Find the original payment and the copay collected for the claim.
  2. Refund the copay to the member and record the refund on the account.
  3. Check the new processing. If the claim was reprocessed with a different patient responsibility, bill or credit that amount as reported.
  4. If another payer is now responsible, bill it. See eligibility and COB denials.
  5. Reconcile any recoupment of the payer’s own payment on the same or a later remittance.

How to prevent problems

  • Verify eligibility and COB before collecting copays at each visit.
  • Post reversals promptly so refunds aren’t missed.
  • Track N857 with ERA Analyzer to see how often reversals cause patient refunds.

Codes that may appear with N857

  • PR-3 (Co-payment Amount): The co-payment amount being reversed.
  • CO-A0 (Patient refund amount.): Patient refund amount.
  • N783 (Alert: Patient is a Medicaid/ Qualified Medicare Beneficiary.): An alert to review records for wrongly collected copayments from Medicaid or QMB patients.
  • CO-B13 (Previously paid.): Previously paid, where a payment may have been made on an earlier claim.

N857 FAQ

Why would a claim be reversed?

Common reasons are retroactive eligibility changes, coordination of benefits corrections, duplicate processing, or a corrected claim replacing the original.

Do I have to refund the copay even if the service is still owed?

N857 tells you to refund the copay. If a different amount is owed after reprocessing, the new remittance will show it; bill that instead.

How quickly should I refund?

Promptly. Some contracts and state laws set refund timeframes. Check your agreements and state rules.