ICD-10 Code E80.3 – Defects of catalase and peroxidase (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E80.3 – Defects of catalase and peroxidase
What it is
E80.3 identifies an inherited disorder involving reduced activity of catalase and peroxidase enzymes. These defects affect how the body handles oxidative stress and may be documented as a metabolic enzyme abnormality.
Clinical signs
Clinical features vary; refer to documentation. Cases may be noted through family history, laboratory or genetic evaluation, or findings consistent with an enzyme defect rather than an acquired illness.
When to use this code
Use E80.3 when the record specifically documents defects of catalase and peroxidase. It fits confirmed congenital or hereditary enzyme abnormalities, including encounters for evaluation or monitoring of the disorder. Do not assign it for nonspecific oxidative stress concerns without a documented diagnosis.
Do not use for
Do not use this code for general anemia, liver disease, or other metabolic problems unless the provider links them to catalase or peroxidase defects. Check documentation if the chart only mentions abnormal labs or suspected enzyme deficiency.
Coding tip
Code E80.3 only when the provider names the enzyme defect; otherwise, query or code the documented condition instead.