Remittance advice remark code

Remark code N4 meaning

RARC N4: The prior insurance carrier's explanation of benefits is missing, incomplete or invalid.

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Remark code
RARC N4
Short name
Prior insurer's EOB missing or invalid
Plain meaning
The prior insurance carrier's explanation of benefits is missing, incomplete or invalid.
Kind
Adds detail to the reason code on the same line.

Plain-English summary written by Rivvi. X12 owns the RARC list and its exact wording, which is not reproduced here. Read it on the X12 RARC list (list dated July 1, 2026, checked October 23, 2026). This page does not decide how a claim is paid.

What to check before resubmitting

  1. Attach the prior payer's EOB, or include its payment data electronically.

Reason codes it often comes with

Related remark codes

Related pages

Questions

What does remark code N4 mean?

The prior insurance carrier's explanation of benefits is missing, incomplete or invalid. This is Rivvi's plain-English summary of RARC N4. X12's exact wording is on x12.org.

What should I do about N4?

Attach the prior payer's EOB, or include its payment data electronically.

Is N4 a denial?

A remark code adds detail to the reason code on the same line. The reason code (CARC) and its group code decide what was denied or adjusted. It is often paired with reason codes 16, 22.

What is the difference between a RARC and a CARC?

A remittance advice remark code (RARC) adds detail to a claim adjustment reason code (CARC). The CARC says why the line was adjusted. The RARC often says what to fix.

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