ICD-10-CM · Chapter 6 · G00-G99
G04 Encephalitis, myelitis and encephalomyelitis
Includes
- acute ascending myelitis
- meningoencephalitis
- meningomyelitis
Excludes 1 (cannot be coded together)
- encephalopathy NOS (G93.40)
Excludes 2 (not included here)
- 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)
Subcodes
Each subcode links to a detail page with full clinical annotations.
| Code | Description | Billable |
|---|---|---|
| G04..0 | Acute disseminated encephalitis and encephalomyelitis (ADEM) | No |
| G04..00 | Acute disseminated encephalitis and encephalomyelitis, unspecified | Yes |
| G04..01 | Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM) | Yes |
| G04..02 | Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis | Yes |
| G04..1 | Tropical spastic paraplegia | Yes |
| G04..2 | Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified | Yes |
| G04..3 | Acute necrotizing hemorrhagic encephalopathy | No |
| G04..30 | Acute necrotizing hemorrhagic encephalopathy, unspecified | Yes |
| G04..31 | Postinfectious acute necrotizing hemorrhagic encephalopathy | Yes |
| G04..32 | Postimmunization acute necrotizing hemorrhagic encephalopathy | Yes |
| G04..39 | Other acute necrotizing hemorrhagic encephalopathy | Yes |
| G04..8 | Other encephalitis, myelitis and encephalomyelitis | No |
| G04..81 | Other encephalitis and encephalomyelitis | Yes |
| G04..82 | Acute flaccid myelitis | Yes |
| G04..89 | Other myelitis | Yes |
| G04..9 | Encephalitis, myelitis and encephalomyelitis, unspecified | No |
| G04..90 | Encephalitis and encephalomyelitis, unspecified | Yes |
| G04..91 | Myelitis, unspecified | Yes |
Last reviewed: September 2026