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N101 Remark Code (Deactivated): Site-of-Service Provider

N101 meant the claim needed the identification number of the provider where the service took place, and the provider should resubmit with it. X12 deactivated it and suggested MA105, which was also later retired; service facility remarks such as N293 cover this now.

X12 deactivated RARCN101 on January 31, 2004. Payers should no longer use it on new remittances, but it can still appear on older ERAs, corrected claims, and appeals.

Code: N101 (RARC N101)
Status: Deactivated StoppedJanuary 31, 2004 (in use since October 31, 2001).
Code set: Remittance Advice Remark Codes (RARC)
Group codes: CO (Contractual Obligation): Accompanied CO missing-information adjustments; the claim had to be resubmitted with the site's identifier.
Official description: Additional information is needed in order to process this claim. Please resubmit the claim with the identification number of the provider where this service took place. The Medicare number of the site of service provider should be preceded with the letters 'HSP' and entered into item #32 on the claim form. You may bill only one site of service provider number per claim.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified: September 24, 2026 against the official X12 list.

What N101 meant

Remark N101 asked for more information before the claim could be processed: the identification number of the provider where the service was performed, typically a hospital or other facility. Its text gave detailed paper-claim instructions, including a prefix and the form item to use, and allowed only one site-of-service number per claim.

What replaced it

X12’s note suggested MA105, a remark about a missing or invalid provider number for the place of service. MA105 was later retired as well. Today the service location is reported in dedicated facility fields, and problems are flagged with N293 for the facility identifier or N294 for its address.

If you still see N101

It only appears in older remittances. For a current rejection, complete the service facility location on the claim with the facility’s details and identifier as the payer requires, and resubmit.

MA105Deactivated (Missing/incomplete/invalid provider number for this place of service.): The suggested replacement, later deactivated too.
N293 (Missing/incomplete/invalid service facility primary identifier.): Missing, incomplete, or invalid service facility primary identifier.
N294 (Missing/incomplete/invalid service facility primary address.): Missing, incomplete, or invalid service facility primary address.

N101 FAQ

What was the 'HSP' instruction in N101's text?

Its paper-claim instructions asked providers to put the site-of-service provider's Medicare number, preceded by the letters HSP, in item 32 of the claim form. That format belongs to older paper claim rules.

How is the service location reported today?

Through the service facility location fields on the claim, using the facility's name, address, and NPI where required.

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