T64
Non-Billable (Header)Toxic effect of aflatoxin and other mycotoxin food contaminants
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
What This Code Means
T64 is the ICD-10-CM diagnosis code for toxic effect of aflatoxin and other mycotoxin food contaminants. T64 sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering toxic effects of substances chiefly nonmedicinal as to source (t51-t65).
Header codes like T64 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at T64's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for T64 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.