E80.1 maps to CMS-HCC V28 50. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

HCC Buddy Code Card

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Code lookupE80.1

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

E80.1

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

Porphyria cutanea tarda

A porphyria disorder causing blistering and fragile skin on sun-exposed areas, often triggered by liver disease or certain medications.

Buddy Insight

Porphyria cutanea tarda (PCT) is the most common porphyria, characterized by photosensitive blistering on sun-exposed skin, skin fragility, hypertrichosis, and hyperpigmentation.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 50

Amyloidosis, Porphyria, and O...

Coefficient HCC 50: 0.648 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 029

HHS-HCC 029 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 23

Other Significant Endocrine a...

Code-level coefficient reference

RXHCC

Mapped

HCC 43

Pituitary, Adrenal Gland, and...

Code-level coefficient reference

Code Book Path

Official

E80Disorders of porphyrin and bilirubin metabolism E80.1Porphyria cutanea tarda

Inclusion Terms

Official

No inclusion terms are included in this display for E80.1. Check the code and parent instructions in the Code Book.

Excludes 2

Official

Ehlers-Danlos syndromes (Q79.6-)Inherited from E70-E88

Related Codes

Official

E80.0Hereditary erythropoietic porphyria E80.2Other and unspecified porphyria E80.3Defects of catalase and peroxidase E80.4Gilbert syndrome E80.5Crigler-Najjar syndrome

Includes

Official

defects of catalase and peroxidaseInherited from E80

Excludes 1

Official

transitory endocrine and metabolic disorders specific to newborn (P70-P74)Inherited from E00-E89, E70-E88
androgen insensitivity syndrome (E34.5-)Inherited from E00-E89, E70-E88
congenital adrenal hyperplasia (E25.0)Inherited from E00-E89, E70-E88
hemolytic anemias attributable to enzyme disorders (D55.-)Inherited from E00-E89, E70-E88
Marfan syndrome (Q87.4-)Inherited from E00-E89, E70-E88
5-alpha-reductase deficiency (E29.1)Inherited from E00-E89, E70-E88

Code First

Official

No Code First sequencing instructions are included in this display for E80.1. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for E80.1. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for E80.1. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Provider diagnosis of porphyria cutanea tarda

Elevated urine and plasma uroporphyrins with characteristic porphyrin pattern

Skin findings: blistering, skin fragility, hypertrichosis, scarring on sun-exposed areas (hands, forearms, face)

Iron studies: ferritin level, hepatic iron assessment

MEAT Support

HCC Buddy guidance

Provider diagnosis of porphyria cutanea tarda

Elevated urine and plasma uroporphyrins with characteristic porphyrin pattern

Skin findings: blistering, skin fragility, hypertrichosis, scarring on sun-exposed areas (hands, forearms, face)

Iron studies: ferritin level, hepatic iron assessment

Audit Caution

HCC Buddy guidance

Not recognizing PCT as a manifestation of underlying liver disease — always evaluate for hepatitis C and hemochromatosis

Confusing PCT with other photosensitive blistering conditions (pseudoporphyria, epidermolysis bullosa acquisita)

Coding PCT as acute porphyria — PCT is a chronic cutaneous porphyria, NOT an acute porphyria

Failing to code the associated conditions (hepatitis C, hemochromatosis, alcohol use disorder) as additional diagnoses

Common Mistakes

HCC Buddy guidance

E80.0 — Hereditary erythropoietic porphyria: much rarer and more severe, with childhood onset

E80.21 — Acute intermittent porphyria: neurovisceral attacks, NOT skin blistering

E80.29 — Other porphyria: for porphyria types like variegate porphyria or hereditary coproporphyria

L10.9 — Pemphigus, unspecified: autoimmune blistering disease that may mimic PCT

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 E80.1 an HCC code?

Yes. E80.1 (Porphyria cutanea tarda) maps to HCC 50, Amyloidosis, Porphyria, and Other Specified Metabolic Disorders under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.648. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: E80.1 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: E80.1
Description: Porphyria cutanea tarda
HCC (V28): HCC 50 — Amyloidosis, Porphyria, and Other Specified Metabolic Disorders
RAF reference coefficient: 0.648
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 50, Amyloidosis, Porphyria, and Other Specified Metabolic Disorders

0.648

ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders

Not separately weighted

RxHCCHCC 43, Pituitary, Adrenal Gland, and Other Endocrine and Metabolic Disorders

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work E80.1 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for E80.1

For E80.1, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

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

Coder workflow notes

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What This Code Means

E80.1 is the ICD-10-CM diagnosis code for porphyria cutanea tarda. A porphyria disorder causing blistering and fragile skin on sun-exposed areas, often triggered by liver disease or certain medications. E80.1 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, E80.1 maps to Amyloidosis, Porphyria, and Other Specified Metabolic Disorders (HCC 50) with a source-labeled community, non-dual, aged reference coefficient of 0.648. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Document triggering factors such as hepatitis C, HIV, or medication use. For E80.1, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for E80.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document triggering factors such as hepatitis C, HIV, or medication use
•Code associated liver disease separately if present

Clinical Significance

Porphyria cutanea tarda (PCT) is the most common porphyria, characterized by photosensitive blistering on sun-exposed skin, skin fragility, hypertrichosis, and hyperpigmentation. It is often associated with hepatic iron overload, hepatitis C, alcohol use, and estrogen exposure, and is the only porphyria primarily treated by phlebotomy to reduce iron stores.

Documentation Requirements

✓Provider diagnosis of porphyria cutanea tarda
✓Elevated urine and plasma uroporphyrins with characteristic porphyrin pattern
✓Skin findings: blistering, skin fragility, hypertrichosis, scarring on sun-exposed areas (hands, forearms, face)
✓Iron studies: ferritin level, hepatic iron assessment
✓Assessment for associated conditions: hepatitis C, alcohol use, hemochromatosis, HIV, estrogen use
✓Treatment plan: therapeutic phlebotomy, low-dose hydroxychloroquine, or iron chelation

Commonly Confused Codes

•E80.0: Hereditary erythropoietic porphyria: much rarer and more severe, with childhood onset
•E80.21: Acute intermittent porphyria: neurovisceral attacks, NOT skin blistering
•E80.29: Other porphyria: for porphyria types like variegate porphyria or hereditary coproporphyria
•L10.9: Pemphigus, unspecified: autoimmune blistering disease that may mimic PCT
•L12.0: Bullous pemphigoid: another blistering condition that may be confused with PCT on sun-exposed skin