Providers with NPIs are required to submit them on all claims. Claims billed without an NPI in MMIS will be denied. Providers are responsible for making sure their NPI information is on file with MassHealth.

Each provider’s NPI is associated with a corresponding MassHealth provider ID and service location (PID/SL). This MMIS ID is 10-characters, made up of a nine-digit base number and an alpha service location (e.g. 123456789A). This ID will be displayed on remittances advices along with the NPI and will be displayed on reports, etc. Only atypical providers should submit claims using the MMIS ID. All other providers must bill using the NPI.

MassHealth will process claims by mapping the NPI submitted on a claim to the MMIS provider number. As some providers have one NPI that corresponds to multiple MMIS provider numbers, MassHealth will crosswalk the NPI submitted on the claim to the correct MMIS provider number using the following claim data in the sequence listed below.

  • Claim Type/Type of Bill
  • Taxonomy
  • Address.

NPI Resources

Recent MassHealth Publications Related to NPI:

Updates from the Centers for Medicare and Medicaid Services (CMS):

CMS Bulletin (PDF) pdf format of npi-cms-bulletin.pdf


If you have any questions about NPI, contact MassHealth Customer Service.

This information is provided by MassHealth.