According to the Centers for Medicare & Medicaid Services, “the National Provider Identifier (NPI) is a Health Insurance Portability and Accountability Act (HIPAA) Administrative Standard. An NPI is unique identification number for covered health care providers, created to improve the efficiency and effectiveness of electronic transmission of health information. Covered health care providers and all health plans and health care clearinghouses must use NPIs in their administrative and financial transactions.” For more information, visit here:
https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNProducts/Downloads/NPI-What-You-Need-To-Know.pdf