How to Credential with Illinois Medicaid (IMPACT PE)

If you are credentialing as a new mental health provider for Illinois Medicaid, everything runs through the state's IMPACT Provider Enrollment (IMPACT PE) system. This process is very specific, a bit opaque, and easy to stall if you miss the first prerequisite. This guide walks through the exact steps, what to expect, and where most people get stuck.

What Is IMPACT PE?

IMPACT PE is the Illinois Department of Healthcare and Family Services' online system for enrolling and managing Medicaid providers.

All individual providers and all group practices must be enrolled here before they can bill Illinois Medicaid. Website: https://hfs.illinois.gov/impact.html

Prerequisite

Before you can even start a Provider Enrollment application in IMPACT, the provider's EIN must be certified with the State of Illinois.

This is where most applications fail.

You must submit both of the following:

• A completed W-9

• The IRS CP-575 (EIN Assignment Letter)

Email both documents to: HFS.W9.IMPACT@illinois.gov

This step applies to:

• Solo providers using an EIN

• Group practices

• PLLCs, LLCs, and corporations

Every new IMPACT account must complete this step, even if they already bill commercial insurance.

Important: You Will NOT Get a Confirmation Email

• The state does not confirm when the EIN is certified

• There is no ticket number

• There is no reply email

So how do you know when it's done?

You must log back into IMPACT and try to create a new Provider Enrollment application.

• If it is not processed yet, you will still see an EIN verification error

• Once it is processed, the error disappears and the application proceeds

Usually it takes 1-2 weeks for this to complete

Starting the Provider Enrollment Application

Once the EIN is certified:

• Log into IMPACT

• Start a New Provider Enrollment

• Select the correct provider type (individual vs group)

• Complete all required ownership, taxonomy, and location sections.

Filling out the Provider Checklist

After you submit the enrollment application, IMPACT generates a Provider Checklist.

This checklist must be completed in full and typically includes:

• License verification

• Ownership and control disclosures

• Practice location details

• Electronic funds transfer (EFT) setup

• Additional attestations

Tip: Make sure the info matches the NPPES Registry or the application will get kicked back

Timeline

The general timeline once complete is roughly 90-120 days. If it gets kicked back, expect another 90 days from the time it was kicked back.

Final Thoughts

Illinois Medicaid enrollment is not hard, but it is procedural. The system assumes you already know the order of operations, and it gives very little feedback when something is missing.

If you remember only one thing, make it this: EIN certification via W-9 and CP-575 always comes first.

Once that is done, the rest of the IMPACT process becomes straightforward and predictable.