G70.01 ICD-10-CM Code: Myasthenia gravis with (acute) exacerbation
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)
G70.01
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMyasthenia gravis with (acute) exacerbation
A sudden worsening of myasthenia gravis, an autoimmune condition where muscles become weak and tire easily, particularly affecting the eyes, face, and limbs.
Buddy Insight
Myasthenia gravis with acute exacerbation represents a sudden worsening that can progress to myasthenic crisis with respiratory failure, requiring emergency intervention.
CMS-HCC V28
MappedHCC 195
RAF 0.0
CMS-HCC V24
MappedHCC 75
RAF 0.425
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 75
RAF 0.0
RXHCC
MappedHCC 153
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Myasthenia gravis in crisis
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G70.01 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G70.01 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G70.01 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G70.01 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G70.01 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G70.01 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 G70.01 an HCC code?
Yes. G70.01 maps to Myasthenia Gravis with (Acute) Exacerbation under the CMS-HCC V28 risk adjustment model (and Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome 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 G70.01
For G70.01to 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 G70.01 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G70.01 is the ICD-10-CM diagnosis code for myasthenia gravis with (acute) exacerbation. A sudden worsening of myasthenia gravis, an autoimmune condition where muscles become weak and tire easily, particularly affecting the eyes, face, and limbs. G70.01 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, G70.01 maps to Myasthenia Gravis with (Acute) Exacerbation (HCC 195) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, G70.01 maps to Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome (HCC 75) with a community, non-dual, aged base RAF weight of 0.425. 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.
Use this code only when documentation indicates an acute exacerbation or worsening of myasthenia gravis symptoms. Because G70.01 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 G70.01 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when documentation indicates an acute exacerbation or worsening of myasthenia gravis symptoms
- •Do not use this code for stable or controlled myasthenia gravis; use G70.00 instead
Clinical Significance
Myasthenia gravis with acute exacerbation represents a sudden worsening that can progress to myasthenic crisis with respiratory failure, requiring emergency intervention. This higher-acuity code reflects significantly increased resource utilization including potential ICU admission, plasmapheresis, or intravenous immunoglobulin. Accurate coding distinguishes these high-risk encounters from routine management visits.
Documentation Requirements
- ✓Clear documentation of acute worsening of myasthenia gravis symptoms
- ✓Specific symptoms of exacerbation: increased weakness, dysphagia, respiratory compromise, ptosis worsening
- ✓Comparison to baseline function demonstrating deterioration
- ✓Trigger assessment: infection, medication changes, surgical stress
- ✓Acute treatment administered: intravenous immunoglobulin, plasmapheresis, medication adjustment
- ✓Respiratory status monitoring including forced vital capacity measurements
Commonly Confused Codes
- •G70.00: Myasthenia gravis without exacerbation is for the stable chronic state; use G70.01 only when acute worsening is documented
- •J96.00: Acute respiratory failure may need to be coded additionally if the exacerbation causes respiratory compromise
- •G70.80: Lambert-Eaton syndrome has similar muscle weakness but different pathophysiology and treatment
- •G73.3: Myasthenic syndromes in other diseases is for secondary myasthenic symptoms, not primary myasthenia gravis