E80.0 ICD-10-CM Code: Hereditary erythropoietic porphyria
E80.0 maps to CMS-HCC V28 50 (RAF 0.648). Documentation must support MEAT. MEAT criteria · RAF calculator · HCC Buddy coding tools
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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)
E80.0
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceHereditary erythropoietic porphyria
A rare inherited blood disorder causing severe light sensitivity, blistering skin, and red-colored urine from birth or early childhood.
Buddy Insight
Hereditary erythropoietic porphyria (Gunther disease) is the rarest and most severe cutaneous porphyria, caused by deficiency of uroporphyrinogen III synthase.
CMS-HCC V28
MappedHCC 50
RAF 0.648
CMS-HCC V24
MappedHCC 23
RAF 0.194
ACA/HHS
MappedHCC 29
Varies by metal level
ESRD/PACE
MappedHCC 23
RAF 0.036
RXHCC
MappedHCC 43
RAF 0.063
Code Book Path
Inclusion Terms
Official- Congenital erythropoietic porphyria
- Erythropoietic protoporphyria
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for E80.0 in this effective period.
Related Child Codes
Includes
Official- defects of catalase and peroxidase
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for E80.0 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for E80.0 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for E80.0 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for E80.0 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is E80.0 an HCC code?
Yes. E80.0 (Hereditary erythropoietic porphyria) maps to Amyloidosis, Porphyria, and Other Specified Metabolic Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24), with a community non-dual aged RAF of 0.648. It is billable for payment year 2026.
Coder answer: E80.0 is billable and maps to V28 HCC 50, Amyloidosis, Porphyria, and Other Specified Metabolic Disorders. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- E80.0
- Description
- Hereditary erythropoietic porphyria
- HCC (V28)
- HCC 50 — Amyloidosis, Porphyria, and Other Specified Metabolic Disorders
- RAF
- 0.648
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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.
Work E80.0 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for E80.0
For E80.0 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 E80.0 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
E80.0 is the ICD-10-CM diagnosis code for hereditary erythropoietic porphyria. A rare inherited blood disorder causing severe light sensitivity, blistering skin, and red-colored urine from birth or early childhood. E80.0 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, E80.0 maps to Amyloidosis, Porphyria, and Other Specified Metabolic Disorders (HCC 50) with a community, non-dual, aged base RAF weight of 0.648. Under the older CMS-HCC V24 model, E80.0 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.194. 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.
Document severity and presence of photosensitivity complications. Because E80.0 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 E80.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document severity and presence of photosensitivity complications
- •Code associated skin damage or infections separately
Clinical Significance
Hereditary erythropoietic porphyria (Gunther disease) is the rarest and most severe cutaneous porphyria, caused by deficiency of uroporphyrinogen III synthase. It presents in infancy with severe photosensitivity causing blistering, scarring, and mutilation of sun-exposed skin, hemolytic anemia, splenomegaly, and red-brown staining of teeth (erythrodontia).
Documentation Requirements
- ✓Provider diagnosis of hereditary erythropoietic porphyria or congenital erythropoietic porphyria
- ✓Markedly elevated urinary and fecal uroporphyrin and coproporphyrin levels
- ✓Clinical manifestations: severe photosensitivity, skin blistering and scarring, erythrodontia, hemolytic anemia
- ✓Splenomegaly assessment
- ✓Genetic testing showing UROS gene mutations if performed
- ✓Sun protection measures and management plan (hematopoietic stem cell transplant consideration)
Commonly Confused Codes
- •E80.1: Porphyria cutanea tarda: much more common, acquired, milder cutaneous porphyria in adults
- •E80.20: Unspecified porphyria: avoid when the specific type is documented
- •E80.21: Acute intermittent porphyria: hepatic porphyria with neurovisceral crises, not erythropoietic
- •L56.0: Drug phototoxic response: photosensitivity in porphyria is metabolic, not drug-induced