G71.220 ICD-10-CM Code: X-linked myotubular myopathy
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Diseases of myoneural junction and muscle (G70-G73)
G71.220
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceX-linked myotubular myopathy
X-linked myotubular myopathy is a rare inherited muscle disease that primarily affects males, causing severe muscle weakness and difficulty with movement and breathing. The condition is caused by a genetic mutation passed down through families and typically appears in infancy or early childhood.
Buddy Insight
X-linked myotubular myopathy is the most severe form of centronuclear myopathy, predominantly affecting males and typically presenting at birth with profound hypotonia and respiratory failure.
CMS-HCC V28
MappedHCC 197
RAF 0.0
CMS-HCC V24
MappedHCC 76
RAF 0.358
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 76
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Myotubular (centronuclear) myopathy
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G71.220 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G71.220 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G71.220 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G71.220 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G71.220 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G71.220 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is G71.220 an HCC code?
Yes. G71.220 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 G71.220
For G71.220to 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 G71.220 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G71.220 is the ICD-10-CM diagnosis code for x-linked myotubular myopathy. X-linked myotubular myopathy is a rare inherited muscle disease that primarily affects males, causing severe muscle weakness and difficulty with movement and breathing. The condition is caused by a genetic mutation passed down through families and typically appears in infancy or early childhood. G71.220 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, G71.220 maps to Muscular Dystrophy (HCC 197) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G71.220 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 code is specific to X-linked inheritance pattern; do not use if the myotubular myopathy is autosomal recessive or of unknown inheritance type. Because G71.220 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 G71.220 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code is specific to X-linked inheritance pattern; do not use if the myotubular myopathy is autosomal recessive or of unknown inheritance type
- •Document the family history and genetic testing results in the medical record to support the X-linked classification, as this distinction is critical for accurate coding and genetic counseling
Clinical Significance
X-linked myotubular myopathy is the most severe form of centronuclear myopathy, predominantly affecting males and typically presenting at birth with profound hypotonia and respiratory failure. Most patients require lifelong ventilatory support. This code carries significant risk adjustment importance given the extreme care complexity and resource utilization associated with this condition.
Documentation Requirements
- ✓Genetic testing confirming MTM1 gene mutation on the X chromosome
- ✓Clinical presentation: severe neonatal hypotonia, respiratory failure at birth
- ✓Muscle biopsy showing centrally placed nuclei (myotubular fibers) when available
- ✓X-linked inheritance pattern: male patient, carrier mother
- ✓Respiratory support requirements: ventilator type, hours of use
- ✓Feeding method: oral versus gastrostomy tube
- ✓Provider's explicit diagnosis specifying X-linked myotubular myopathy
Commonly Confused Codes
- •G71.228 — Other centronuclear myopathy is for autosomal dominant or recessive forms, not X-linked
- •G71.20 — Congenital myopathy, unspecified should not be used when X-linked myotubular myopathy is confirmed
- •G71.21 — Nemaline myopathy has rod-shaped inclusions on biopsy, not central nuclei
- •P94.2 — Congenital hypotonia is a symptom code and should not replace the specific myopathy diagnosis