Skip to content
HCC Buddy home

G70.01 ICD-10-CM Code: Myasthenia gravis with (acute) exacerbation

G70.01 maps to CMS-HCC V28 195. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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 guidance

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.

Buddy the Bee presenting code insight

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

HCC 195

Code-level coefficient reference

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 115

Code-level coefficient reference

ESRD/PACE

HCC 75

Code-level coefficient reference

RXHCC

HCC 153

Code-level coefficient reference

Code Book Path

Official
G70Myasthenia gravis and other myoneural disorders
G70.0Myasthenia gravis
G70.01Myasthenia gravis with (acute) exacerbation

Inclusion Terms

Official
  • Myasthenia gravis in crisis

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G70.01 in this effective period.

Related Child Codes

Official
G70.00Myasthenia gravis without (acute) exacerbation

Includes

Official

ICD-10-CM does not list Includes notes for G70.01 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G70.01 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G70.01 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G70.01 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G70.01 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
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

MEAT Support

HCC Buddy guidance
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

Audit Caution

HCC Buddy guidance
Using this code for routine visits when the patient has chronic stable myasthenia gravis — exacerbation must be explicitly documented
Not coding the exacerbation status when the provider documents worsening symptoms during the encounter
Failing to add respiratory failure codes when myasthenic crisis involves respiratory compromise
Confusing medication titration adjustments for symptom management with actual acute exacerbation

Common Mistakes

HCC Buddy guidance
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

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is G70.01 an HCC code?

Yes. G70.01 (Myasthenia gravis with (acute) exacerbation) maps to HCC 195, Myasthenia Gravis with (Acute) Exacerbation under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 2.909. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: G70.01 is billable and maps to V28 HCC 195, Myasthenia Gravis with (Acute) Exacerbation. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
G70.01
Description
Myasthenia gravis with (acute) exacerbation
HCC (V28)
HCC 195 — Myasthenia Gravis with (Acute) Exacerbation
RAF reference coefficient
2.909
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 195, Myasthenia Gravis with (Acute) Exacerbation
2.909
ESRDHCC 75, Myasthenia Gravis/Myoneural Disorders and Guillain-Barre Syndrome/Inflammatory and Toxic Neuropathy
Not separately weighted
RxHCCHCC 153, Myasthenia Gravis and Other Myoneural Disorders
Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work G70.01 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for G70.01

For G70.01 to 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.

Coder workflow notes

Get the V28 mapping + MEAT cheat sheet

One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.

Free PDF. No card. Unsubscribe anytime.

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 source-labeled community, non-dual, aged reference coefficient of 2.909. No V24 mapping is shown for G70.01; use the applicable model and payment year when reviewing the V28 mapping. 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. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Use this code only when documentation indicates an acute exacerbation or worsening of myasthenia gravis symptoms. Because G70.01 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. 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, source-labeled coefficient references, 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

Child Codes

G70.00Myasthenia gravis without (acute) exacerbation
HCC 196
G70.01Myasthenia gravis with (acute) exacerbation
HCC 195

Code Hierarchy

└G70Myasthenia gravis and other myoneural disorders└G70.0Myasthenia gravis└G70.01Myasthenia gravis with (acute) exacerbation
└G70.01Myasthenia gravis with (acute) exacerbation

Because G70.01 maps to an HCC category, the documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment.

G70.01 maps to CMS-HCC V28 category 195, Myasthenia Gravis with (Acute) Exacerbation. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for G70.01. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

More on G70.01

Referenced in blog posts

Work G70.01 in HCC Buddy

Open G70.01 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

Open in Code BookOpen in EncoderStart Pro