MedicaidAdministrativeMedium impact
IMPORTANT INFORMATION Reporting of National Provider Identifier (NPI)
Illinois Medicaid - HFS·IL·Provider Notice
Effective date
May 23, 2008
We identified it
Jun 21, 2026
Summary
The implementation of NPI requirements for Other Physician IDs (Prescribing, Attending, Operating) has been delayed from July 1, 2008. However, billing providers must now include their NPI on all claims submitted to Illinois Medicaid, while continuing to use legacy provider numbers on adjustment forms, OPO forms, and prior approval forms.
Action Required
Immediately: Billing team must ensure billing provider's NPI is included on all paper, direct data entry, and electronic claims to Illinois Medicaid. For paper claims, report NPI in the same field previously used for HFS Legacy Provider Number (except UB04 forms which have designated NPI fields). Continue using HFS Legacy Provider Numbers on paper adjustment forms, Optical Prescription Order forms, and prior approval forms - do not substitute NPI on these forms.