I needed to get the NPI number of our company. We are in the Special Education industry. Our billing dept couldn't tell me what it is. I tried the NPPES NPI Registry and I guess that worked but tried others as well since there are so many sites that claims they perform NPI Lookups. NPIR.org seems to be my fav since it was the easiest to use and was really fast. Just wanted to say kudos to them for creating such an easy site to use.