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N403 Remark Code: Missing Facility Certification

N403 means the payer needed documentation of the facility's certification to cover the service, and it was not received.

Quick facts

Code
N403 (RARC N403)
Status
Active In use since August 1, 2007.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The claim is denied until the certification is documented. It is a provider or facility responsibility; the patient is not billed.
Official description
Missing facility certification.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N403 means

Some services can only be paid when they’re performed in a certified facility. The certification might come from a federal program, an accrediting body, or the payer itself. N403 says the payer needed evidence of that certification and didn’t receive it.

It usually pairs with CARC 252, and with CARC B7 when the payer treats the provider as not certified for the date.

Common causes

  • The facility’s certification was renewed and the payer’s file still shows the expired one.
  • The service moved to a new location that hasn’t been added to the certification record the payer has.
  • The payer requested the certificate and the request wasn’t answered.
  • The claim’s service facility information didn’t match the certified location.

What to do

  1. Identify the certification the payer needs for this service, from its request or policy.
  2. Get a current copy showing the facility name, address, certification number, and effective dates covering the date of service.
  3. Check the claim’s service location (box 32 and 32a on the CMS-1500, or the service facility on the 837) matches the certified site.
  4. Submit the certificate as the payer instructs, with the claim number.
  5. Update enrollment so future claims aren’t held for the same reason. See provider enrollment denials for enrollment updates.

How to prevent it

Track certification expiration dates for every site and send renewals to each payer as soon as they are issued. When opening or moving a location, update payer enrollment before billing services that require certification.

Codes that may appear with N403

  • CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): An attachment is required; N403 identifies the facility certification.
  • CO-B7 (This provider was not certified/eligible to be paid for this procedure/service on this date of service.): The provider was not certified or eligible to be paid for this service on this date.
  • N404 (Incomplete/invalid facility certification.): Used when the facility certification was received but is incomplete or invalid.
  • MA120 (Missing/incomplete/invalid CLIA certification number.): Covers a missing or invalid CLIA certification number for lab services.
  • N92 (This facility is not certified for digital mammography.): States the facility is not certified for digital mammography.

N403 FAQ

What kind of facility certification do payers ask for?

Examples include certifications for mammography, laboratory testing, and designation as an approved center for certain procedures. Each payer and service has its own requirements.

Isn't certification already on file with the payer?

Sometimes it is recorded during enrollment, but payers may still request current documentation, especially after a renewal or a change of location.

What if the facility wasn't certified on the date of service?

Then submitting documentation won't help. The claim may not be payable for that date.