45 C.F.R. § 162.406 Standard unique health identifier for health care providers.
Title 45 - Public Welfare
(a) Standard. The standard unique health identifier for health care providers is the National Provider Identifier (NPI). The NPI is a 10-position numeric identifier, with a check digit in the 10th position, and no intelligence about the health care provider in the number. (b) Required and permitted uses for the NPI. (1) The NPI must be used as stated in §162.410, §162.412, and §162.414. (2) The NPI may be used for any other lawful purpose.
Title 45: Public Welfare
PART 162—ADMINISTRATIVE REQUIREMENTS
Subpart D—Standard Unique Health Identifier for Health Care Providers
§ 162.406 Standard unique health identifier for health care providers.

