E70.321
BillableTyrosinase positive oculocutaneous albinism
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E70.321 an HCC code?
Yes. E70.321 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.
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 E70.321
For E70.321 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 E70.321 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E70.321 is the ICD-10-CM diagnosis code for tyrosinase positive oculocutaneous albinism. A genetic condition where the body has reduced melanin production affecting skin, hair, and eyes, with some enzyme activity present allowing minimal pigment formation. E70.321 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 older CMS-HCC V24 model, E70.321 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.
Tyrosinase positive indicates some enzyme function; patients may have more pigmentation than tyrosinase negative type. Because E70.321 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 E70.321 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Tyrosinase positive indicates some enzyme function; patients may have more pigmentation than tyrosinase negative type
- •Document the degree of pigmentation and any associated complications
Clinical Significance
Tyrosinase-positive oculocutaneous albinism (Type 2) involves reduced but not absent melanin production, with some residual tyrosinase enzyme activity. Patients typically develop some pigmentation over time, particularly in hair and skin, though still significantly less than normal. Visual impairment is generally less severe than in the tyrosinase-negative form, but patients still require ophthalmologic management and dermatologic surveillance for skin cancer risk.
Documentation Requirements
- ✓Documentation should include confirmation of residual tyrosinase activity through enzyme assay or genetic testing, description of pigmentation present in skin, hair, and eyes, ophthalmologic findings including visual acuity and presence of nystagmus, and comparison with family members if relevant.
- ✓Note any progressive development of pigmentation over time.
- ✓Dermatologic monitoring plan and sun protection measures should be documented.
Commonly Confused Codes
- •E70.320 (Tyrosinase negative oculocutaneous albinism) has complete enzyme deficiency with no pigmentation.
- •E70.329 (Oculocutaneous albinism, unspecified) does not specify enzyme status.
- •E70.328 (Other oculocutaneous albinism) covers non-standard variants.
- •E70.30 (Albinism, unspecified) is far less specific.
- •L80 (Vitiligo) is acquired depigmentation, not genetic.