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N879 Remark Code: Consent Not Allowed for Service

N879 is an alert that the notice and consent the patient signed cannot waive No Surprises Act protections for these services. The plan calculated payment and cost sharing under the Act, and balance billing is prohibited.

Code: N879 (RARC N879)
Status: Active In use since March 1, 2022.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): The amount above the No Surprises Act payment and the patient's share. It is not collectible from the patient.
PR (Patient Responsibility): In-network-level cost sharing for the protected service.
Official description: Alert: The notice and consent to balance bill, and to be charged out-of-network cost sharing, that was obtained from the patient with regard to the billed services, is not permitted for these services. Thus, cost sharing and the total amount paid have been calculated based on the requirements under the No Surprises Act, and balance billing is prohibited.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N879 means

Notice and consent is a narrow exception. Patients can waive surprise-billing protections only for certain scheduled, non-emergency services from out-of-network providers at in-network facilities. Many services are carved out entirely.

N879 means the plan looked at the service billed and decided it falls in a category where consent does not count. That is different from N878, where the form itself was defective. Here, the issue is the service type or the circumstances, so no amount of paperwork would have changed the result.

Common causes

An ancillary specialty, such as anesthesia or radiology, collected a consent form at a participating facility.
The service was emergency care, or post-stabilization care where the patient could not give meaningful consent.
The need for the service arose unexpectedly during the visit.
No participating provider was available at the facility.

What to do

Accept the in-network cost sharing as the patient’s full responsibility and refund any overpayment.
Review the plan’s payment separately and use open negotiation if you believe the rate is too low.
Update front-desk and scheduling rules so consent forms are not collected for excluded services, which can give patients the wrong impression about what they owe.

Codes that may appear with N879

CO-45 (Charge exceeds fee schedule/maximum allowable or contracted/legislated fee arrangement.): The reduction to the out-of-network amount the Act allows.
PR-2 (Coinsurance Amount): Coinsurance calculated at the in-network level.

N878 (Alert: The provider or facility specified that notice was provided and consent to balance bill obtained, but notice and consent was not provided and…): Consent was permitted for the service but was not obtained correctly.
N864 (Alert: This claim is subject to the No Surprises Act provisions that apply to emergency services.): Flags that No Surprises Act rules for emergency services applied.
N866 (Alert: This claim is subject to the No Surprises Act provisions that apply to services furnished by nonparticipating providers of air ambulance…): Flags the Act's rules for nonparticipating air ambulance providers, where consent cannot be used.

N879 FAQ

Which services can never use notice and consent?

Emergency services and air ambulance cannot. At in-network facilities, ancillary services such as emergency medicine, anesthesiology, pathology, radiology, neonatology, assistant surgeon, hospitalist, and intensivist services, plus diagnostic services, are also excluded, as are unforeseen urgent needs.

Does a perfectly executed form change the outcome?

No. For services on the excluded list, even a correctly completed form does not allow balance billing.

What about an N879 when a participating alternative was unavailable?

Consent is also not allowed when no participating provider was available at the facility to furnish the service.

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