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N665 Remark Code: Provider Not Licensed

N665 means the payer denied the service because it shows the provider who performed it was not licensed, either at all, in that state, or on that date. Payers generally do not pay for services from unlicensed practitioners.

Code: N665 (RARC N665)
Status: Active In use since July 15, 2013.
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): The service is not payable and the provider bears the loss. It is generally not appropriate to bill the patient.
Official description: Services by an unlicensed provider are not reimbursable.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N665 means

Payers pay for services only from practitioners who are legally allowed to provide them, which in most cases means holding an active license in the state where the care was delivered. N665 tells you the payer concluded the practitioner on the claim didn’t meet that standard for the date of service.

The finding may be accurate, or it may reflect stale data. Payers check licenses at credentialing and through periodic updates, and their records can lag behind a renewal or a new state license.

Common causes

The license expired and the renewal hadn’t been reported to the payer.
The provider was licensed in another state but delivered care, including telehealth, to a patient located in a state where they weren’t licensed.
Work by a trainee, assistant, or other staff member was billed under their own identifier.
The wrong rendering NPI was reported in box 24J, pointing to someone without a license on file.
The license was suspended or restricted during the dates of service.

How to fix it

Verify the license through the state licensing board for the date of service and the state where the patient was treated.
If the license was valid, send the payer proof and ask it to update the provider record, then request reprocessing or file an appeal.
If the wrong provider was billed, correct box 24J and send a corrected claim with resubmission code 7 in box 22.
If the provider wasn’t licensed, the service generally can’t be billed to this payer. Review your compliance obligations and whether any payments already received must be returned.

How to prevent it

Track license expiration dates for every clinician and update payers as soon as renewals are issued. Check licensure before scheduling telehealth patients located in other states. See provider enrollment denials for the broader credentialing workflow.

Codes that may appear with N665

CO-185 (The rendering provider is not eligible to perform the service billed.): The rendering provider is not eligible to perform the service billed.
CO-170 (Payment is denied when performed/billed by this type of provider.): Payment is denied when performed or billed by this type of provider.

N732 (Services performed at an unlicensed facility are not reimbursable.): Services performed at an unlicensed facility are not reimbursable.
M143 (The provider must update license information with the payer.): The provider must update license information with the payer.
N612 (Medical provider not authorized/certified to provide treatment to injured workers in this jurisdiction.): A workers' compensation remark: the provider isn't authorized to treat injured workers in that jurisdiction.

N665 FAQ

The provider is licensed. Why did we get N665?

The payer's records may show an expired license, a license in a different state, or a license type that doesn't match. Send the payer current license information and ask it to update its records.

What if the service was done by an unlicensed staff member under supervision?

Some payers allow certain services by supervised staff to be billed under the supervising provider, and others don't. The rules vary by payer and state, so check them before billing.

Can we appeal?

Yes, if the provider was properly licensed on the date of service. Include proof of the license and its effective dates.

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