HIPAA Information - Where are the Implementation Guides, Code Sets, and Rules?
A:
The home page for the National Plan and Provider Enumeration System (NPPES), the registry for the NPI (National Provider Identifier) is at https://nppes.cms.hhs.gov/NPPES/Welcome.do
CPT-4, or Level 1 HCPCS, is maintained and licensed by the American Medical Association and is available for purchase in various hardcopy and softcopy formats from of variety of vendors.