E80.3
BillableDefects of catalase and peroxidase
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E80.3 an HCC code?
Yes. E80.3 maps to Glycogen/Amino-Acid/Other Metabolic Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for E80.3
For E80.3 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E80.3 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E80.3 is the ICD-10-CM diagnosis code for defects of catalase and peroxidase. A rare genetic condition where the body lacks or has defective enzymes (catalase or peroxidase) that normally break down harmful hydrogen peroxide in cells. E80.3 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the CMS-HCC V28 risk adjustment model, E80.3 maps to Glycogen/Amino-Acid/Other Metabolic Disorders (HCC 50) with a community, non-dual, aged base RAF weight of 0.289. Under the older CMS-HCC V24 model, E80.3 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This is a rare metabolic disorder; ensure documentation clearly identifies the specific enzyme deficiency. Because E80.3 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E80.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a rare metabolic disorder; ensure documentation clearly identifies the specific enzyme deficiency
- •May be associated with other systemic manifestations that should be coded separately
Clinical Significance
Defects of catalase and peroxidase includes acatalasia (catalase deficiency), also known as Takahara disease. While often asymptomatic, affected individuals may develop oral ulcerations and gangrene due to inability to decompose hydrogen peroxide. Myeloperoxidase deficiency, the most common inherited neutrophil disorder, is also captured here.
Documentation Requirements
- ✓Specific enzyme deficiency documented (catalase deficiency/acatalasia or peroxidase deficiency/myeloperoxidase deficiency)
- ✓Confirmatory enzyme activity testing or genetic testing
- ✓Clinical manifestations: oral ulcers and gangrene (acatalasia), recurrent infections (myeloperoxidase deficiency)
- ✓Functional impact on patient's health
- ✓Treatment and management plan
Commonly Confused Codes
- •D71 — Functional disorders of polymorphonuclear neutrophils: myeloperoxidase deficiency may be coded here as a neutrophil function disorder
- •E80.29 — Other porphyria: peroxidase defects are not porphyrias despite being in the same section
- •K12.1 — Other forms of stomatitis: oral ulcers in acatalasia need the metabolic code, not just the symptom code
- •E80.20 — Unspecified porphyria: do not confuse catalase/peroxidase defects with porphyrias