Welcome to the Illinois Medicaid Provider Directory. Effective October 1, 2019 all Ordering, Referring and Prescribing providers must be enrolled through Illinois Medicaid Program Advanced Cloud Technology (IMPACT) as a participating individual practitioner. To confirm if a provider is actively enrolled with Illinois Medicaid, please use the search features. Only those providers listed in this directory may be used to Order/Refer/Prescribe services for Illinois Medicaid beneficiaries.