Traditional MedicareAdministrativeMedium impact
Re:
Illinois Medicaid - HFS·IL·Provider Notice
Effective date
Jun 16, 2021
We identified it
Jun 20, 2026
Summary
Illinois Medicaid now requires claim filing indicator code "MB" (Medicare B) in Loop 2320, Segment SBR09 for 837P crossover claims submitted through clearinghouses for patients with both Original Medicare and Medicare Advantage. Claims without this code will be rejected with error K22.
Action Required
Immediately: Billing team must update clearinghouse submissions to include claim filing indicator code "MB" in Loop 2320, Segment SBR09 for all 837P Medicare crossover claims. Inform clearinghouse vendors of this mapping change requirement. Claims missing this code will be rejected with error K22 - MBI Does Not Match # on File.