MedicaidBilling CodesHigh impact
Ambulatory Procedures Listing (APL) Conversion to HCPCS/CPT Codes
Illinois Medicaid - HFS·IL · Emergency Medicine, General Surgery·Provider Notice
Effective date
Jul 1, 2004
We identified it
Jun 21, 2026
Summary
Effective July 1, 2004, all hospital outpatient and ambulatory surgical treatment center claims must use HCPCS/CPT codes instead of ICD-9 procedure codes. Emergency department and observation services now require specific CPT codes paired with corresponding revenue codes, and claims with only ICD-9 procedure codes will be rejected.
Action Required
By July 1, 2004: Billing team must update all hospital outpatient and ASTC claims to use HCPCS/CPT codes in FL 44 of UB-92 forms and Loop ID 2400 of 837I electronic claims. Emergency department claims must pair specific CPT codes with revenue codes (450 with 99284/99285, 456 with 99282/99283, 451 with 99281). Observation services must use revenue code 762 with CPT codes 99218-99220 or 99234-99236. Split any series claims that span July 1, 2004. Claims submitted with only ICD-9 procedure codes will be rejected.