ICDwise
G04 ⚠ Non-billable

Encephalitis, myelitis and encephalomyelitis

ICD-10-CM · FY2026 · Diseases of the Nervous System

Code
G04
System
ICD-10-CM
Billable
No — use specific code
Effective
FY2026
Chapter
Diseases of the Nervous System
Source
CMS / CDC NCHS
⚠ Verify before billing. Confirm against the current CMS/NCHS ICD-10-CM files and your payer's rules before claims submission.

Official coding notes

From CMS's ICD-10-CM Tabular List.

Includes
  • acute ascending myelitis
  • meningoencephalitis
  • meningomyelitis
Excludes1 — never code together
  • encephalopathy NOS (G93.40)
Excludes2 — not included here, but may code together
  • acute transverse myelitis (G37.3)
  • alcoholic encephalopathy (G31.2)
  • multiple sclerosis (G35-)
  • myalgic encephalomyelitis (G93.32)
  • subacute necrotizing myelitis (G37.4)
  • toxic encephalitis (G92.8)
  • toxic encephalopathy (G92.8)

Frequently asked questions

What is ICD-10 code G04?
ICD-10-CM code G04 represents Encephalitis, myelitis and encephalomyelitis. It is a non-billable header code requiring a more specific subcategory in the Diseases of the Nervous System chapter, effective October 1, 2025 – September 30, 2026.
Is G04 billable?
No. G04 is a non-billable header. Select a more specific subcategory for claims submission.
What chapter is G04 in?
G04 belongs to the Diseases of the Nervous System chapter (G00–G99) of ICD-10-CM.

Related codes in the G04 category

G04.0 Acute disseminated encephalitis and encephalomyelitis (ADEM) Non-billable G04.1 Tropical spastic paraplegia Billable G04.2 Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified Billable G04.3 Acute necrotizing hemorrhagic encephalopathy Non-billable G04.8 Other encephalitis, myelitis and encephalomyelitis Non-billable G04.9 Encephalitis, myelitis and encephalomyelitis, unspecified Non-billable G04.00 Acute disseminated encephalitis and encephalomyelitis, unspecified Billable G04.01 Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM) Billable

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