MedicaidBilling CodesHigh impact
Change in Billing for Anesthesia Effective with Claims Received on and after October 1, 2021
Illinois Medicaid - HFS·IL · Anesthesiology·Provider Notice
Effective date
Oct 1, 2021
We identified it
Jun 20, 2026
Summary
Effective October 1, 2021, anesthesiologists and CRNAs must use anesthesia CPT codes (00100-01999) when billing for anesthesia units instead of surgical procedure codes. Claims submitted with surgical codes will be rejected with error code N41.
Action Required
Immediately: Billing team must update all anesthesia claims to use appropriate anesthesia CPT codes in range 00100-01999 instead of surgical procedure codes. Update billing software rules and encounter forms. Train anesthesiologists and CRNAs on new requirement. Claims submitted with surgical codes will be rejected with error code N41.