The NPI Searchable Database is Here 

The Centers for Medicare & Medicaid Services has released a searchable database and downloadable file that health care providers and others can use to verify National Provider Identifier data for claims and billing purposes. More on CMS' policy for disseminating the NPI data can be found in a presentation available online.

May 24 was the deadline for health care providers and most health plans to implement NPIs for standard electronic transactions under the Health Insurance Portability and Accountability Act. However, entities that acted in "good faith" to become NPI compliant can accept legacy numbers through May 23, 2008, under a CMS contingency plan.