G71.228
BillableOther centronuclear myopathy
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G71.228 an HCC code?
Yes. G71.228 maps to Muscular Dystrophy under the CMS-HCC V28 risk adjustment model (and Muscular Dystrophy 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 G71.228
For G71.228to 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 G71.228 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G71.228 is the ICD-10-CM diagnosis code for other centronuclear myopathy. A congenital muscle disease where nuclei are abnormally positioned in the center of muscle fibers, causing weakness, excluding the common autosomal recessive form. G71.228 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering diseases of myoneural junction and muscle (g70-g73).
Under the CMS-HCC V28 risk adjustment model, G71.228 maps to Muscular Dystrophy (HCC 197) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G71.228 mapped to the same category but with a base RAF weight of 0.358 — V28 recalibrated weights across the entire model. 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.
Distinguish between different centronuclear myopathy subtypes; this code is for 'other' types not separately classified. Because G71.228 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 G71.228 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Distinguish between different centronuclear myopathy subtypes; this code is for 'other' types not separately classified
- •Document the inheritance pattern and genetic testing results when available to support specificity
Clinical Significance
Other centronuclear myopathy encompasses autosomal dominant and autosomal recessive forms of centronuclear myopathy, excluding the X-linked form. These conditions vary widely in severity from mild adult-onset to severe neonatal presentations. Accurate coding distinguishes these from X-linked myotubular myopathy and supports appropriate genetic counseling and management planning.
Documentation Requirements
- ✓Muscle biopsy showing centrally placed nuclei in muscle fibers
- ✓Genetic testing identifying the specific mutation (DNM2 for autosomal dominant, BIN1 for autosomal recessive, etc.)
- ✓Inheritance pattern documentation (not X-linked)
- ✓Clinical severity and age of onset
- ✓Respiratory and functional status assessment
- ✓Provider's explicit diagnosis of centronuclear myopathy specifying non-X-linked type
Commonly Confused Codes
- •G71.220 — X-linked myotubular myopathy is the X-linked form specifically; use G71.228 for autosomal forms
- •G71.21 — Nemaline myopathy has nemaline rods, not centrally placed nuclei
- •G71.20 — Congenital myopathy, unspecified should not be used when centronuclear pathology is confirmed
- •G71.29 — Other congenital myopathy is for structural myopathies without central nuclei