CommercialBilling CodesHigh impact
20-1026 Check Diagnosis Codes to Avoid Claim Denials
Health Net·CA·Coding
Effective date
Mar 1, 2021
We identified it
Jun 20, 2026
Summary
Health Net is implementing stricter NCCI coding edits starting March 1, 2021, to reduce claim denials for incorrect ICD-10 diagnosis code sequencing. Claims will be denied for common coding errors like using manifestation codes as primary diagnoses, incorrect chemotherapy diagnosis coding, and incomplete diagnosis codes.
Action Required
Immediately: Billing team must review and update coding practices to ensure correct ICD-10 diagnosis sequencing per NCCI standards. Train coders on proper sequencing: chemotherapy encounters require Z51.11 or Z51.12 as primary diagnosis, manifestation codes cannot be primary diagnoses, sequela codes must be sequenced after the condition code, and external cause codes cannot be first-listed. Update billing software edits to flag denial code 255 and EXwd errors. Review ICD-10 Manual before resubmitting denied claims.