2027 ICD-10-CM Diagnosis Code G70.01Myasthenia gravis with (acute) exacerbation
ICD-10-CM Codes›G00–G99›G70-G73›G70
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Risk Adjusts — HCC 195
- Chronic Condition
G70.01 is a billable ICD-10-CM diagnosis code for myasthenia gravis with (acute) exacerbation. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 56 through 57. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 72 closely related codes. Coders also document this condition as myasthenia gravis with exacerbation. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myopathies.
For Medicare Advantage risk adjustment, G70.01 maps to CMS-HCC Category 195 (Myasthenia Gravis with (Acute) Exacerbation) under the V28 model, adding a risk factor of about 2.909 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
G70.01 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Myasthenia gravis with exacerbation
- Myasthenic crisis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G70.01: its own notes plus those printed at G70 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Myasthenia gravis in crisis
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name G70.01, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming G70.01: they are not reported together with it, unless the two conditions are unrelated.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
with exacerbation (acute) G70.01
in crisis G70.01
with exacerbation (acute) G70.01
in crisis G70.01
Paralysis, paralytic (complete) (incomplete) G83.9
with exacerbation (acute) G70.01
in crisis G70.01
with exacerbation (acute) G70.01
in crisis G70.01
Syndrome See Also: Disease;
with exacerbation (acute) G70.01
in crisis G70.01
with exacerbation (acute) G70.01
in crisis G70.01
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Myasthenia Gravis
a disorder of neuromuscular transmission characterized by fatigable weakness of cranial and skeletal muscles with elevated titers of acetylcholine receptors or muscle-specific receptor tyrosine kinase (musk) autoantibodies. clinical manifestations may include ocular muscle weakness (fluctuating, asymmetric, external ophthalmoplegia; diplopia; ptosis; and weakness of eye closure) and extraocular fatigable weakness of facial, bulbar, respiratory, and proximal limb muscles. the disease may remain limited to the ocular muscles (ocular myasthenia). thymoma is commonly associated with this condition.
Patient EducationClinical
Myasthenia Gravis
Myasthenia gravis, sometimes called MG, is a chronic (long-lasting) disease that causes weakness in your voluntary muscles. The voluntary muscles are the ones that you can control. They include the muscles you use for:
The full article covers:
- What is myasthenia gravis?
- What causes myasthenia gravis?
- Who is more likely to develop myasthenia gravis?
- What are the symptoms of myasthenia gravis?
- How is myasthenia gravis diagnosed?
- What are the treatments for myasthenia gravis?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G70.01 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G70.01Overview
What is the ICD-10 code for myasthenia gravis with (acute) exacerbation?
The ICD-10-CM code for myasthenia gravis with (acute) exacerbation is G70.01 (sometimes written as G7001). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G70.01 (Myasthenia gravis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report myasthenia gravis with (acute) exacerbation on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G70.01 group to?
When myasthenia gravis with (acute) exacerbation is the principal diagnosis on an inpatient stay, it groups to MS-DRG 57, 56, with relative weights from 1.2835 to 2.2649 depending on complications. Higher weights mean higher Medicare reimbursement.
Is G70.01 a CC or MCC?
CMS lists G70.01 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 72 closely related codes in its exclusion list.
Can G70.01 be reported with A05.1?
Not as a rule. The Excludes1 note at G70, which applies to G70.01, lists "botulism (A05.1, A48.51-A48.52)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is G70.01?
G70.01 (myasthenia gravis with (acute) exacerbation) maps to CMS-HCC Category 195 (Myasthenia Gravis with (Acute) Exacerbation), commonly written as HCC 195, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 75 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 153.
Does G70.01 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, G70.01 adds a risk adjustment factor of about 2.909 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 1.779 to 3.633 depending on the payment segment). HCC 195 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 195 category page.
