Skip to main content

N266 Remark Code: Ordering Provider Address Issue

N266 means the address of the ordering provider was missing, incomplete, or invalid. It mainly appears on claims where the payer wants the ordering clinician's practice location, which is most common for durable medical equipment and supplies.

Quick facts

Code
N266 (RARC N266)
Status
Active In use since December 2, 2004.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The supplier or billing provider can correct the address and resubmit; the patient is not responsible.
Official description
Missing/incomplete/invalid ordering provider address.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N266 means

Most claims identify an ordering provider by name and NPI only. For certain services, especially durable medical equipment, prosthetics, orthotics, and supplies, the electronic claim can also carry the ordering clinician’s address and contact details. When a payer requires the address and it is blank, partial, or unusable, it returns N266.

It is usually paired with CARC 16 and resolved with a corrected claim.

Common causes

  • The DME or supply order was entered without the clinician’s practice address, so the 837P ordering section went out with no address lines.
  • The supplier’s own address was copied into the ordering provider fields by default.
  • The address had no ZIP code, an incomplete city and state, or a formatting error such as the suite in the city field.
  • The order came from a clinician who has since moved practices, and the address on file is stale.

What to do

  1. Look at the written order or prescription for the ordering clinician’s practice address.
  2. Cross-check it against NPPES for the ordering NPI. If they differ, confirm with the ordering office which location is current.
  3. Enter the full street address, city, state, and ZIP in the ordering provider setup, not on a per-claim note.
  4. Rebuild the claim and send it as a replacement with frequency code 7.

How to prevent it

Suppliers who bill ordered items regularly should maintain an ordering-clinician directory keyed by NPI, with address and phone refreshed from NPPES. When an order arrives, pick the clinician from that directory rather than typing details by hand. A scrubber rule that requires an ordering address on DME claims for payers that expect it will catch gaps before submission.

For the other ordering-provider data problems, compare N264, N265, and N268, and see how CARC 16 missing-information denials work.

Codes that may appear with N266

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): A submission error; N266 narrows it to the ordering provider's address.
  • N264 (Missing/incomplete/invalid ordering provider name.): Ordering provider name is the problem instead.
  • N265 (Missing/incomplete/invalid ordering provider primary identifier.): Ordering provider NPI is the problem instead.
  • N268 (Missing/incomplete/invalid ordering provider contact information.): Ordering provider contact information, such as phone, is the problem.
  • N258 (Missing/incomplete/invalid billing provider/supplier address.): The billing provider's address, not the ordering provider's, is the problem.

N266 FAQ

Is there a CMS-1500 box for the ordering provider's address?

No. The paper form carries only the ordering name and NPI in box 17 and 17b. The address travels in the ordering provider section of the 837P, which is why N266 is mostly an electronic-claim issue.

Which address should I use?

The ordering clinician's practice location, ideally as it appears in NPPES or on the order, not your own office or a billing address.

Why would a payer care about the ordering address?

It helps confirm the ordering clinician's identity and location, and some payers use it for jurisdiction or program-integrity checks on ordered items.