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N313 Remark Code: Certification Revision Date

N313 means the certification revision date was missing, incomplete, or invalid. When a certification, such as a DME certificate of medical necessity or a therapy plan of care, is revised, the payer needs the date of that revision.

Quick facts

Code
N313 (RARC N313)
Status
Active In use since December 2, 2004.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): Provider-correctable; supply the right revision date and resubmit. The patient does not owe the amount.
Official description
Missing/incomplete/invalid certification revision date.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N313 means

Certifications establish that a service or item is needed for a defined period. When something about the prescription changes mid-period, payers often require a revised certification, and the claim then needs to show the revision date so the payer can apply the updated terms. N313 means the date wasn’t present or couldn’t be accepted.

It is usually reported with CARC 16. If the payer also needs to see the revised certification, CARC 252 may appear.

Common causes

  • The claim was flagged as a revised certification, but the revision date wasn’t entered.
  • The initial certification date was repeated in the revision field.
  • The revision date falls before the initial certification or after the date of service.
  • The prescriber signed the revised document after the service, and the claim used the signature date without meeting the payer’s rules.
  • A revision was needed (for example, a change in oxygen flow) but the claim still reflected the original certification.

How to fix it

  1. Review the certification history for the patient: initial date, any revisions, and recertifications.
  2. Confirm that the revised certification exists, is signed, and covers the service dates.
  3. Enter the correct revision date and make sure the certification type on the claim indicates a revision.
  4. If the payer requires the document, attach or send it through its documentation channel.
  5. Resubmit with frequency code 7.

How to prevent it

Keep certification events in a single timeline per patient and item, rather than separate notes. When a prescription changes, trigger a task to obtain a revised certification before billing the next period. Suppliers who manage many rentals benefit from a report of upcoming revisions and recertifications, which prevents both N313 and related documentation denials.

Codes that may appear with N313

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Missing or invalid information; N313 names the certification revision date.
  • CO-252 (An attachment/other documentation is required to adjudicate this claim/service.): Documentation, such as the revised certification itself, is required.
  • N322 (Missing/incomplete/invalid last certification date.): The last certification date is missing or invalid.
  • N227 (Incomplete/invalid Certificate of Medical Necessity.): The certificate of medical necessity is incomplete or invalid.
  • M60 (Missing Certificate of Medical Necessity.): The certificate of medical necessity is missing.

N313 FAQ

When is a certification 'revised'?

When the original certification changes during the certified period, for example because the prescribed amount, equipment, or treatment frequency changed. Payers define revision events in their own rules.

Is a revision the same as a recertification?

No. A recertification renews the certification for another period. A revision changes the existing certification within its period.

Where is the date reported?

It depends on the claim type and payer. DME claims carry certification dates in the certification information of the electronic claim; follow the payer's companion guide.