MedicaidBilling CodesHigh impact
20-1028 Check Diagnosis Codes to Avoid Claim Denials
Health Net·CA · Oncology·Prior Authorization
Effective date
Mar 1, 2021
We identified it
Jun 20, 2026
Summary
Health Net CalViva Health will enforce NCCI coding standards and ICD-10 requirements for Medi-Cal claims in Fresno, Kings and Madera counties, with specific denial codes for incorrect diagnosis code sequencing, chemotherapy coding, and other coding errors. Claims with improper diagnosis code positioning or invalid codes will be denied with specific denial codes.
Action Required
Immediately: Billing team must review all claim submissions to ensure proper ICD-10 diagnosis code sequencing per NCCI standards. Verify chemotherapy claims include Z51.11 or Z51.12 as primary diagnosis unless administered for non-neoplastic conditions. Update billing system edits to catch manifestation codes in primary position, ensure secondary diagnoses are properly positioned, and validate all diagnosis codes are complete and active for date of service. Train staff to reference ICD-10 Manual before resubmitting denied claims with codes EXwd or denial code 255.