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20-1027 Check Diagnosis Codes to Avoid Claim Denials

Health Net·CA·Coding
Effective date
Mar 1, 2021
We identified it
Jun 20, 2026
Days to comply

Summary

Health Net will begin enforcing NCCI and ICD-10 coding standards effective March 1, 2021, with specific edits for diagnosis code sequencing, chemotherapy coding, and preventive services. Claims with incorrect diagnosis code positioning or missing secondary diagnoses will be denied with specific denial codes.

Action Required

Action needed
Immediately: Billing team must review and update all coding practices to ensure proper ICD-10 diagnosis code sequencing per NCCI standards. Verify chemotherapy claims use Z51.11 or Z51.12 as primary diagnosis, secondary diagnoses are in second position, manifestation codes are not used as primary, and external cause codes are not sequenced first. Train staff on denial code EXwd (255) for resubmission requirements. Claims with incorrect sequencing will be denied.

Affected Billing Codes

Z51.11
Z51.12
Z51.0