2026 ICD-10-CM Diagnosis Code G37.3Acute transverse myelitis in demyelinating disease of central nervous system

ICD-10-CM Codes›G00–G99›G35-G37›G37

ICD-10-CM G37.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G37.3 is a billable ICD-10-CM diagnosis code for acute transverse myelitis in demyelinating disease of central nervous system. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as acute non-infective transverse myelitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (neither hereditary nor degenerative).

Code Identity

ICD-10-CM Code
G37.3
Billable Status
Yes — Valid for Submission
Code Describes
Acute transverse myelitis in demyelinating disease of central nervous system
Short Description
Acute transverse myelitis in demyelinating disease of cnsl
Parent Code
G37
Other demyelinating diseases of central nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG35-G37Demyelinating diseases of the central nervous system
CategoryG37Other demyelinating diseases of central nervous system
This CodeG37.3Acute transverse myelitis in demyelinating disease of central nervous system

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute non-infective transverse myelitis
  • Acute transverse myelitis
  • Acute viral transverse myelitis
  • Complete transverse myelitis
  • Herpes zoster myelitis
  • Idiopathic transverse myelitis
  • Transverse myelopathy syndrome
  • Varicella transverse myelitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Acute transverse myelitis NOS
  • Acute transverse myelopathy

Type 1 Excludes

  • acute flaccid myelitis G04.82
  • multiple sclerosis G35
  • neuromyelitis optica Devic G36.0

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.

    • Myelitis(acute) (ascending) (childhood) (chronic) (descending) (diffuse) (disseminated) (idiopathic) (pressure) (progressive) (spinal cord) (subacute)
      • transverse (in demyelinating diseases of central nervous system)
    • Myelopathy(spinal cord)
      • transverse, acute

Clinical ClassificationClinical

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

CCSR NVS020
Other nervous system disorders (neither hereditary nor degenerative)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Acute Transverse Myelitis

    a neurologic disorder that is caused by inflammation across both sides of one level, or segment, of the spinal cord. (from ninds)

  • Acute Transverse Myelitis in Demyelinating Disease of Central Nervous System|Acute transverse myelitis in demyelinating disease of central nervous system

    evidence of acute transverse myelitis in demyelinating disease of the central nervous system.

Patient EducationClinical

Neurologic Diseases

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G37.3 to ICD-9-CMHistory

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

ICD-9-CM
341.20 Acute myelitis NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
341.21 Acute myelitis oth cond
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 G37.3Overview

Is G37.3 (Other demyelinating diseases of central nervous system) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acute transverse myelitis in demyelinating disease of central nervous system on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G37.3?

Under the General Equivalence Mappings, acute transverse myelitis in demyelinating disease of central nervous system converts to ICD-9-CM 341.20 (acute myelitis NOS) and 341.21 (acute myelitis oth cond). 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.