MedicaidBilling CodesHigh impact
Billing for Chemotherapy Administration
Illinois Medicaid - HFS·IL · Oncology, Hematology·Provider Notice
Effective date
Apr 13, 2006
We identified it
Jun 21, 2026
Summary
Medicaid billing requirements for chemotherapy administration have changed. Providers must use standard CPT codes instead of Medicare's temporary C-Series HCPCS codes, as C-Series codes will cause Medicaid claim rejections.
Action Required
Immediately: Billing team must stop using C-Series HCPCS codes on Medicaid chemotherapy administration claims and switch to appropriate CPT chemotherapy administration codes. Update billing system rules to prevent C-Series codes on Medicaid claims. For Medicare crossover claims, ensure both C-Series codes AND CPT codes are included. Claims with only C-Series codes will be denied.