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N831 Remark Code: Revalidation Request Not Answered

N831 means the payer denied or held the claim because the provider or supplier did not respond to requests to revalidate its enrollment information. Until revalidation is completed and processed, claims may not be paid.

Quick facts

Code
N831 (RARC N831)
Status
Active In use since March 1, 2020.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The denial is due to the provider's enrollment status and is not billable to the patient.
Official description
You have not responded to requests to revalidate your provider/supplier enrollment information.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N831 means

Enrollment isn’t permanent. Medicare and many Medicaid programs and plans periodically ask providers to revalidate: confirm their practice locations, ownership, licenses, and other enrollment details. N831 means the payer sent revalidation requests and received no response, and it is now acting on that by denying or holding claims.

N831 is the consequence code. N550 is the related alert that often shows up earlier warning that failure to revalidate will affect billing. When N831 appears, the provider’s billing privileges may already be deactivated, and CARC B7 or 185 typically explains the denial.

Common causes

  • Requests sent to an outdated address or an email inbox no one monitors.
  • Staff turnover in the credentialing role, leaving due dates untracked.
  • Incomplete submission that the payer returned or rejected without a follow-up.
  • Revalidation submitted for the group but not for individual clinicians, or the other way round.

How to fix it

  1. Check enrollment status in the payer’s portal (for Medicare, the online enrollment system) to confirm whether billing privileges are deactivated.
  2. Submit the revalidation with all required information and fees, if applicable, as soon as possible.
  3. Confirm the effective date once the payer approves or reactivates enrollment.
  4. Resubmit held or denied claims for dates the payer will cover. Ask the payer how to handle dates during the lapse.
  5. Watch timely filing on held claims. See timely filing denials.

How to prevent it

  • Keep a credentialing calendar with every payer’s revalidation due date for the group and each clinician.
  • Keep your correspondence address and contact person current with every payer.
  • See provider enrollment denials for enrollment maintenance practices.

Codes that may appear with N831

  • 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 on the date of service.
  • CO-185 (The rendering provider is not eligible to perform the service billed.): The rendering provider isn't eligible to perform or bill the service.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Some payers report it as missing required provider information.
  • N550 (Alert: You have not responded to requests to revalidate your provider/supplier enrollment information.): The earlier warning that failing to revalidate will affect billing privileges.
  • N790 (Provider/supplier not accredited for product/service.): The supplier lacks accreditation for the item, a different credential gap.
  • N808 (Not covered for this provider type / provider specialty.): The service isn't covered for the provider's type or specialty.

N831 FAQ

What is revalidation?

Payers periodically ask enrolled providers to confirm or update their enrollment information. Medicare, for example, requires revalidation on a regular cycle and may deactivate billing privileges when providers don't respond.

Will claims be paid once I revalidate?

Not necessarily for every date. Whether claims for dates during a lapse can be paid depends on the payer's rules and when your billing privileges were reinstated.

How do I find out when revalidation was due?

Check the payer's enrollment portal or revalidation lookup, and review mail sent to your correspondence address. Medicare publishes revalidation due dates online.