All PlansBilling CodesHigh impact
ICD-10-CM Implementation
Illinois Medicaid - HFS·IL·Provider Notice
Effective date
Oct 1, 2015
We identified it
Jun 20, 2026
Summary
The federally-mandated conversion from ICD-9 to ICD-10 diagnosis codes takes effect October 1, 2015. All medical providers must begin using ICD-10-CM codes for diagnosis coding on all claims submitted after this date.
Action Required
By October 1, 2015: Billing team must update all billing systems to use ICD-10-CM diagnosis codes instead of ICD-9 codes. Update EMR templates and encounter forms to reflect new coding system. Train all providers and billing staff on ICD-10 code selection. Contact Bureau of Professional and Ancillary Services at 1-877-782-5565, Option 3 for professional billing questions or Option 2 for institutional billing questions. Claims submitted with ICD-9 codes after October 1st will be rejected.