What is ICD-10 code E74.02?

E74.02 is the ICD-10-CM diagnosis code for Pompe disease. A rare inherited disorder where the body cannot break down glycogen due to acid maltase enzyme deficiency, causing muscle weakness and heart problems. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E74.02 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E74.02 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. E74.02 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. E74.02 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.

Which HCC does E74.02 map to under V28?

E74.02 maps to CMS-HCC V28 49 (Specified Lysosomal Storage Disorders). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does E74.02 pay in RAF?

E74.02 carries a community, non-dual, aged (CNA) RAF weight of 9.256 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for E74.02?

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. For E74.02, V28 maps to Specified Lysosomal Storage Disorders at RAF 9.256 while V24 mapped to Other Significant Endocrine and Metabolic Disorders at RAF 0.194. Both models can still appear in legacy data and in payer-specific lookback periods.

What documentation supports E74.02?

Document the age of onset (infantile, juvenile, or adult form) as this affects severity and prognosis Note any cardiac involvement or respiratory muscle weakness, as these are key features of Pompe disease Because E74.02 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. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM E74.02: Pompe disease

E74.02 maps to CMS-HCC V28 49 (RAF 9.256). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupE74.02Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

E74.02

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

Pompe disease

A rare inherited disorder where the body cannot break down glycogen due to acid maltase enzyme deficiency, causing muscle weakness and heart problems.

Buddy Insight

CMS-HCC V28

Mapped

HCC 49

Specified Lysosomal Storage D...

RAF 9.256

CMS-HCC V24

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.194

ACA/HHS

Mapped

HCC 27

HHS-HCC 27

Varies by metal level

ESRD/PACE

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.036

RXHCC

Mapped

HCC 41

Lysosomal Storage Disorders

RAF 3.081

Code Book Path

Official

E74Other disorders of carbohydrate metabolism

E74.0Glycogen storage disease

E74.02Pompe disease

Inclusion Terms

Official

Cardiac glycogenosis
Type II glycogen storage disease

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E74.02 in this effective period.

Related Child Codes

Official

E74.00Glycogen storage disease, unspecified

E74.01von Gierke disease

E74.03Cori disease

E74.04McArdle disease

E74.05Lysosome-associated membrane protein 2 [LAMP2] deficiency

Includes

Official

ICD-10-CM does not list Includes notes for E74.02 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for E74.02 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E74.02 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E74.02 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E74.02 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed diagnosis of Pompe disease or GSD Type II

Acid alpha-glucosidase enzyme assay results or GAA gene mutation analysis

Form specification: infantile-onset, late-onset, or childhood-onset

Cardiac evaluation including echocardiogram findings if infantile form

MEAT Support

HCC Buddy guidance

Confirmed diagnosis of Pompe disease or GSD Type II

Acid alpha-glucosidase enzyme assay results or GAA gene mutation analysis

Form specification: infantile-onset, late-onset, or childhood-onset

Cardiac evaluation including echocardiogram findings if infantile form

Audit Caution

HCC Buddy guidance

Coding only the cardiomyopathy or myopathy without identifying the underlying Pompe disease

Failing to distinguish infantile-onset from late-onset Pompe, which have different clinical trajectories

Not coding respiratory failure or ventilator dependence as additional diagnoses when present

Confusing Pompe disease with other causes of hypertrophic cardiomyopathy in infants

Common Mistakes

HCC Buddy guidance

E74.00 — Glycogen storage disease, unspecified: do not use when Pompe disease is documented

E74.05 — LAMP2 deficiency (Danon disease): also causes cardiomyopathy with glycogen accumulation but is a different enzyme

E74.04 — McArdle disease: muscle-only GSD but involves myophosphorylase, not acid maltase

I42.8 — Other cardiomyopathies: cardiomyopathy is a manifestation of Pompe, code the underlying cause

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 E74.02 an HCC code?

Yes. E74.02 (Pompe disease) maps to Specified Lysosomal Storage 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 9.256. It is billable for payment year 2026.

Coder answer: E74.02 is billable and maps to V28 HCC 49, Specified Lysosomal Storage Disorders. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: E74.02
Description: Pompe disease
HCC (V28): HCC 49 — Specified Lysosomal Storage Disorders
RAF: 9.256
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 49, Specified Lysosomal Storage Disorders

9.256

V24HCC 23, Other Significant Endocrine and Metabolic Disorders

0.194

ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders

0.036

RxHCCHCC 41, Lysosomal Storage Disorders

3.081

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 E74.02 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E74.02

For E74.02 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 E74.02 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E74.02 is the ICD-10-CM diagnosis code for pompe disease. A rare inherited disorder where the body cannot break down glycogen due to acid maltase enzyme deficiency, causing muscle weakness and heart problems. E74.02 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, E74.02 maps to Specified Lysosomal Storage Disorders (HCC 49) with a community, non-dual, aged base RAF weight of 9.256. Under the older CMS-HCC V24 model, E74.02 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 the age of onset (infantile, juvenile, or adult form) as this affects severity and prognosis. Because E74.02 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 E74.02 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document the age of onset (infantile, juvenile, or adult form) as this affects severity and prognosis
•Note any cardiac involvement or respiratory muscle weakness, as these are key features of Pompe disease

Clinical Significance

Pompe disease (Glycogen Storage Disease Type II) is caused by acid alpha-glucosidase (acid maltase) deficiency, leading to progressive glycogen accumulation in muscles including the heart and diaphragm. The infantile form causes fatal cardiomyopathy, while late-onset forms cause progressive limb-girdle weakness and respiratory failure. Enzyme replacement therapy (Lumizyme/Myozyme) has transformed outcomes but requires lifelong infusions.

Documentation Requirements

✓Confirmed diagnosis of Pompe disease or GSD Type II
✓Acid alpha-glucosidase enzyme assay results or GAA gene mutation analysis
✓Form specification: infantile-onset, late-onset, or childhood-onset
✓Cardiac evaluation including echocardiogram findings if infantile form
✓Pulmonary function testing documenting respiratory muscle involvement
✓Enzyme replacement therapy status and response to treatment

Commonly Confused Codes

•E74.00: Glycogen storage disease, unspecified: do not use when Pompe disease is documented
•E74.05: LAMP2 deficiency (Danon disease): also causes cardiomyopathy with glycogen accumulation but is a different enzyme
•E74.04: McArdle disease: muscle-only GSD but involves myophosphorylase, not acid maltase
•I42.8: Other cardiomyopathies: cardiomyopathy is a manifestation of Pompe, code the underlying cause
•G72.9: Myopathy, unspecified: muscle weakness is a symptom, not the primary diagnosis