Noridian Medicare
https://www.noridianmedicare.com
National Drug Code Directory
http://www.accessdata.fda.gov/scripts/cder/ndc/dsp_searchresult.cfm
Medicare Coverage Database
https://www.cms.gov/medicare-coverage-database/overview-and-quick-search.aspx
NPI Registry Search
https://npiregistry.cms.hhs.gov/registry/provider-search