E74.03
BillableCori disease
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E74.03 an HCC code?
Yes. E74.03 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).
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 E74.03
For E74.03to 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 E74.03 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E74.03 is the ICD-10-CM diagnosis code for cori disease. A rare inherited metabolic disorder where the body cannot properly process glycogen due to debranching enzyme deficiency, causing muscle weakness and liver problems. E74.03 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, E74.03 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, E74.03 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.
Also known as Forbes disease; document presence of hepatomegaly and muscle symptoms. Because E74.03 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 E74.03 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Also known as Forbes disease; document presence of hepatomegaly and muscle symptoms
- •This condition typically has a better prognosis than other glycogen storage diseases
Clinical Significance
Cori disease (Glycogen Storage Disease Type III), also known as Forbes disease, is caused by glycogen debranching enzyme deficiency. It primarily affects the liver and muscles, causing hepatomegaly, hypoglycemia, and progressive myopathy. While generally milder than von Gierke disease, it can lead to liver cirrhosis and cardiomyopathy in adulthood. Accurate capture ensures risk adjustment reflects the ongoing monitoring and dietary management needs.
Documentation Requirements
- ✓Confirmed diagnosis of Cori disease, Forbes disease, or GSD Type III
- ✓Enzyme assay or genetic testing confirming debranching enzyme deficiency
- ✓Subtype specification if documented (IIIa — liver and muscle; IIIb — liver only)
- ✓Physical exam findings including hepatomegaly and muscle weakness assessment
- ✓Laboratory values including creatine kinase, liver enzymes, and fasting glucose
- ✓Current dietary management and monitoring plan
Commonly Confused Codes
- •E74.01 — von Gierke disease (Type I): also causes hepatomegaly and hypoglycemia but involves different enzyme
- •E74.00 — Glycogen storage disease, unspecified: do not use when Cori disease is confirmed
- •E74.04 — McArdle disease (Type V): pure muscle GSD without liver involvement
- •E74.09 — Other glycogen storage disease: for GSD types without individual codes
- •K76.89 — Other specified diseases of liver: hepatic complications should be coded separately