The National Provider Identifier (NPI) is a Health Insurance Portability and Accountability Act (HIPAA) Administrative Simplification Standard. The NPI is a unique identification number for covered health care providers. The NPI is a 10-position, intelligence-free numeric identifier (10-digit number). Beginning May 23, 2007 (May 23, 2008, for small health plans), the NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions.

Frequently Asked Questions (FAQs)

• Medicare Part A FAQs

Provider Enrollment and NPI

Important Enrollment information includes a link to these CMS documents

• Enrollment and NPI Information
• The Who, What, When, Why & How of NPI
• Medicare Subpart Expectations Paper
• Obtaining Additional NPIs to Resolve Claim Issues - Group/Organizations Only 

Enrollment Guidelines  

NPI EDI Edits

A high level summary of the NPI EDI edits, the type of edit and the effective dates 

• NPI Edits 
• X12N Transaction User Guide 

CMS NPI Links

• CMS NPI website
• NPPES website