2026 ICD-10-CM Diagnosis Code G70.2Congenital and developmental myasthenia

ICD-10-CM Codes›G00–G99›G70-G73›G70

ICD-10-CM G70.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G70.2 is a billable ICD-10-CM diagnosis code for congenital and developmental myasthenia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myopathies.

Code Identity

ICD-10-CM Code
G70.2
Billable Status
Yes — Valid for Submission
Code Describes
Congenital and developmental myasthenia
Short Description
Congenital and developmental myasthenia
Same as the full description in the CMS dataset.
Parent Code
G70
Myasthenia gravis and other myoneural disorders

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG70-G73Diseases of myoneural junction and muscle
CategoryG70Myasthenia gravis and other myoneural disorders
This CodeG70.2Congenital and developmental myasthenia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acetylcholine resynthesis deficiency
  • Amyotonia congenita
  • Congenital end-plate acetylcholine receptor deficiency
  • Congenital myasthenic syndrome
  • Congenital myasthenic syndrome with glycosylation defect due to ALG14 UDP-N-acetylglucosaminyltransferase subunit gene mutation
  • Familial infantile myasthenia
  • Genetically determined myasthenia
  • Myasthenia gravis, juvenile form
  • Pseudomyopathic myasthenia

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Amyotonia
      • congenita
    • Myasthenia
      • congenital
    • Myasthenia
      • developmental
    • Oppenheim's disease

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS018
Myopathies
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Congenital Myasthenic Syndrome

    a group of rare genetic neuromuscular disorders characterized by neuromuscular junction defects. the defects are classified as presynaptic, synaptic, or postsynaptic. signs and symptoms include muscle weakness, easy fatigability, feeding and respiratory difficulties, and scoliosis.

  • Congenital Myasthenic Syndrome 12|CMS12

    an autosomal recessive form of congenital myasthenic syndrome caused by mutation(s) in the gfpt1 gene, encoding glutamine--fructose-6-phosphate aminotransferase 1.

  • Congenital Myasthenic Syndrome 5|CMS5|EAD|Endplate Acetylcholinesterase Deficiency

    congenital myasthenic syndrome caused by mutation(s) in the colq gene, encoding acetylcholinesterase collagenic tail peptide. it is inherited in an autosomal recessive manner.

  • Congenital Myasthenic Syndrome-4C|CMS4C|Myasthenic Syndrome, Congenital, 4C, Associated with Acetylcholine Receptor Deficiency

    an autosomal recessive form of congenital myasthenic syndrome caused by mutation(s) in the chrne gene, encoding acetylcholine receptor subunit epsilon.

  • Presynaptic Congenital Myasthenic Syndrome 6|CMS6

    congenital myasthenic syndrome caused by mutation(s) in the chat gene, encoding choline o-acetyltransferase. it is inherited in an autosomal recessive manner.

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 G70.2 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
358.8 Myoneural disorders NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G70.2Overview

Is G70.2 (Myasthenia gravis and other myoneural disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report congenital and developmental myasthenia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G70.2?

Under the General Equivalence Mappings, congenital and developmental myasthenia converts to ICD-9-CM 358.8 (myoneural disorders NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.