As a result of the Health Insurance Portability and Accountability Act of 1996 (HIPAA), the Final Rule adopting the NPI as the standard unique identifier for health care providers became effective May 23, 2005. As of this date, health care providers became eligible to receive this 10 position, intelligence-free, numeric identifier assigned by the National Plan and Provider Enumeration System (NPPES). The goal of the NPI is to simplify the administration of the health care system and enable efficient electronic transmission of certain health information.

All health care providers are eligible to receive NPIs. HIPAA covered entities, such as providers completing electronic transactions, must include the NPI to identify covered health care providers in standard transactions as of May 23, 2008.