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The National Provider Identifier

The National Provider Identifier (NPI) is unique identification number for health care providers, including both organizations and individuals. The NPI is a 10-position numeric identifier that allows researchers to identify a unique provider. The NPIs are unencrypted in the RIF data and encrypted in the LDS data for years 1999-2012.  The NPI is unencrypted in the LDS data starting with year 2013.

Accessing the NPPES

Researchers are often interested in a source that provides them with a list of all Medicare professional providers. A full list of all providers with a National Provider Identifier (NPI), both organizations and individuals, can be found in the National Plan and Provider Enumeration System (NPPES). Information in the NPPES can be accessed through a query-able database called the NPI Registry or as a downloadable file (often referred to as the “NPI Downloadable File”).

Opening the Downloadable File

The above link for the NPI Downloadable File provides instructions for opening the file, as well as links to code values, a readme document, and a file header. There is also a separate link for the actual data file. The file is very large and cannot be opened in Microsoft Excel. 

Data Contents

The file is updated weekly and monthly and each updated file contains the most current information from NPPES. Historical downloadable files are not maintained.  NPPES health care provider data that are disclosable under the Freedom of Information Act (FOIA) are released. Details on the variables included can be found by visiting the links above.