N54 remark code

Remittance advice remark code N54. Remark codes add detail to the reason code on the same claim line.

Does not match the authorization

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What N54 means

What was billed does not line up with what the payer pre-certified or authorized for this patient.

An authorization was on file, but the claim differs from it. The difference might be the procedure code, number of units, dates, place of service, provider or facility.

N54 typically explains an authorization reason code such as 197 or 15. The fix is usually to update the authorization or correct the claim, depending on which one is wrong.

Common causes

• A different or additional procedure was performed than the one that was authorized.
• The service date falls outside the authorized date range.
• More units or visits were billed than the authorization allowed.
• The rendering provider or facility differs from the one named on the authorization.

What to do next

1. Compare the claim line by line with the authorization record.
2. If the claim is wrong, correct it to match what was authorized and resubmit.
3. If the service changed for clinical reasons, ask the payer about a retro update to the authorization.
4. Appeal with the clinical notes if the payer refuses to update an authorization that should cover the service.

Related codes

• 197 (reason code) No prior authorization on file
• N640 (remark code) Frequency limit exceeded
• N362 (remark code) Too many days or units