MedicaidBilling CodesHigh impact
ICD-10 Implementation Reminder
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 and procedure codes took effect October 1, 2015. All claims with service dates on or after October 1, 2015 must use ICD-10 codes, while claims with earlier service dates must still use ICD-9 codes. Claims spanning the October 1st date require specific splitting rules based on claim type.
Action Required
Effective October 1, 2015: Billing team must immediately switch to ICD-10 diagnosis and procedure codes for all claims with service dates on or after October 1, 2015. Continue using ICD-9 codes for claims with service dates prior to October 1, 2015. Split claims that span the October 1st date based on service dates, except emergency department and observation claims which should not be split. Update billing software to enforce these date-based coding requirements. Use revised paper claim forms HFS 2210, 2211, and 2212 (revision date R-2-15) for ICD-10 claims. For transportation billing with unknown diagnosis, use default ICD-10 code R69.