G71.20
BillableCongenital myopathy, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G71.20 an HCC code?
Yes. G71.20 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 G71.20
For G71.20to 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 G71.20 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G71.20 is the ICD-10-CM diagnosis code for congenital myopathy, unspecified. A muscle weakness condition present from birth where the specific type cannot be determined or is not further specified. G71.20 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, G71.20 maps to Muscular Dystrophy (HCC 197) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G71.20 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.
This is an unspecified code; use only when the specific type of congenital myopathy cannot be identified from documentation. Because G71.20 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 G71.20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is an unspecified code; use only when the specific type of congenital myopathy cannot be identified from documentation
- •Encourage providers to specify the type (nemaline, centronuclear, etc.) for more precise coding
Clinical Significance
Congenital myopathy, unspecified indicates a muscle disease present from birth that has not been further classified. These conditions cause significant lifelong disability including weakness, hypotonia, and potential respiratory compromise. While unspecified, this code captures the chronic progressive nature of the condition for risk adjustment and signals the need for multidisciplinary pediatric or adult neuromuscular care.
Documentation Requirements
- ✓Congenital onset of muscle weakness: present from birth or early infancy
- ✓Clinical features: hypotonia, delayed motor milestones, proximal or generalized weakness
- ✓Diagnostic workup status: muscle biopsy, genetic testing (pending or inconclusive)
- ✓Documentation of why specific type cannot be determined
- ✓Functional status and respiratory function
- ✓Provider's explicit diagnosis of congenital myopathy
Commonly Confused Codes
- •G71.21 — Nemaline myopathy should be used when characteristic nemaline rods are identified on biopsy
- •G71.220 — X-linked myotubular myopathy should be used when this specific genetic form is confirmed
- •G71.00 — Muscular dystrophy, unspecified involves progressive muscle destruction, while congenital myopathies are typically static or slowly progressive
- •P94.2 — Congenital hypotonia is a symptom code, not a diagnosis code for congenital myopathy