What is ICD-10 code E70.320?

E70.320 is the ICD-10-CM diagnosis code for Tyrosinase negative oculocutaneous albinism. A genetic condition where the body cannot produce melanin, affecting skin, hair, and eyes, with a specific enzyme deficiency that prevents any pigment formation. E70.320 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E70.320 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E70.320 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E70.320 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for E70.320?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. E70.320 was a payment HCC under V24 (Other Significant Endocrine and Metabolic Disorders) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting E70.320?

Tyrosinase negative indicates complete absence of the enzyme; document skin and eye findings Code associated complications such as skin cancer risk, vision problems, or photophobia separately Because E70.320 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

E70.320: Tyrosinase negative oculocutaneous

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupE70.320Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)

E70.320

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Tyrosinase negative oculocutaneous albinism

A genetic condition where the body cannot produce melanin, affecting skin, hair, and eyes, with a specific enzyme deficiency that prevents any pigment formation.

Buddy Insight

Tyrosinase-negative oculocutaneous albinism (Type 1A) is the most severe form of oculocutaneous albinism, caused by complete absence of tyrosinase enzyme activity.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.230

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.0

RXHCC

Mapped

HCC 43

Other Significant Endocrine a...

RAF 0.0

Code Trumping

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Code Book Path

Official

E70.3Albinism

E70.32Oculocutaneous albinism

E70.320Tyrosinase negative oculocutaneous albinism

Inclusion Terms

Official

Albinism I
Oculocutaneous albinism ty-neg

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E70.320 in this effective period.

Related Child Codes

Official

E70.321Tyrosinase positive oculocutaneous albinism

E70.328Other oculocutaneous albinism

E70.329Oculocutaneous albinism, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for E70.320 in this effective period.

Excludes 1

Official

Chediak-Higashi syndrome (E70.330)
Hermansky-Pudlak syndrome (E70.331)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E70.320 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E70.320 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E70.320 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must confirm the complete absence of tyrosinase activity through enzyme assay or genetic testing showing homozygous null mutations in the TYR gene.

Clinical findings should include complete absence of visible pigmentation in skin, hair, and eyes, ophthalmologic examination with iris transillumination and foveal hypoplasia, and visual acuity assessment.

Skin cancer surveillance protocol and sun protection measures should be documented.

MEAT Support

HCC Buddy guidance

Documentation must confirm the complete absence of tyrosinase activity through enzyme assay or genetic testing showing homozygous null mutations in the TYR gene.

Skin cancer surveillance protocol and sun protection measures should be documented.

Audit Caution

HCC Buddy guidance

Distinguish from tyrosinase-positive forms where patients may develop some pigmentation over time.

Do not assign this code without confirmed absence of tyrosinase activity.

Code all skin and eye complications separately, including any skin cancers.

Ensure the provider has documented the specific albinism type rather than using a generic albinism designation.

Common Mistakes

HCC Buddy guidance

E70.321 (Tyrosinase positive oculocutaneous albinism) has some residual pigmentation.

E70.329 (Oculocutaneous albinism, unspecified) does not specify the enzyme status.

E70.328 (Other oculocutaneous albinism) covers non-standard variants.

E70.310-E70.319 (Ocular albinism) involves only the eyes.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is E70.320 an HCC code?

Yes. E70.320 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 23, Other Significant Endocrine and Metabolic Disorders

0.230

ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders

0.000

RxHCCHCC 43, Other Significant Endocrine and Metabolic Disorders

0.000

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 E70.320

For E70.320to 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 E70.320 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

E70.320 is the ICD-10-CM diagnosis code for tyrosinase negative oculocutaneous albinism. A genetic condition where the body cannot produce melanin, affecting skin, hair, and eyes, with a specific enzyme deficiency that prevents any pigment formation. E70.320 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, E70.320 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 negative indicates complete absence of the enzyme; document skin and eye findings. Because E70.320 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 E70.320 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Tyrosinase negative indicates complete absence of the enzyme; document skin and eye findings
•Code associated complications such as skin cancer risk, vision problems, or photophobia separately

Clinical Significance

Tyrosinase-negative oculocutaneous albinism (Type 1A) is the most severe form of oculocutaneous albinism, caused by complete absence of tyrosinase enzyme activity. Patients have white hair, very pale skin, and blue-gray irises with no melanin production throughout life. They face the highest risk of skin cancer among albinism types and have significant visual impairment from foveal hypoplasia, nystagmus, and severe photophobia.

Documentation Requirements

✓Documentation must confirm the complete absence of tyrosinase activity through enzyme assay or genetic testing showing homozygous null mutations in the TYR gene.
✓Clinical findings should include complete absence of visible pigmentation in skin, hair, and eyes, ophthalmologic examination with iris transillumination and foveal hypoplasia, and visual acuity assessment.
✓Skin cancer surveillance protocol and sun protection measures should be documented.

Commonly Confused Codes

•E70.321 (Tyrosinase positive oculocutaneous albinism) has some residual pigmentation.
•E70.329 (Oculocutaneous albinism, unspecified) does not specify the enzyme status.
•E70.328 (Other oculocutaneous albinism) covers non-standard variants.
•E70.310-E70.319 (Ocular albinism) involves only the eyes.
•C44.x (Skin cancer codes) may be needed for malignant complications.