HIPAA Information - Where are the Implementation Guides, Code Sets, and Rules?
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.