G04
ICD-10Non-billable categoryEncephalitis, myelitis and encephalomyelitis
Official ICD-10-CM descriptor (FY2026)
Encephalitis, myelitis and encephalomyelitis
G04 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.
Includes
- acute ascending myelitis
- meningoencephalitis
- meningomyelitis
Excludes1
Not coded here. An Excludes1 code should never be reported at the same time as the code above it.
- encephalopathy NOS (G93.40)
Excludes2
Not included here. The condition is not part of this code, but a patient may have both, and both codes may be reported 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)
More specific codes under G04
- G04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)category
- G04.1Tropical spastic paraplegia
- G04.2Bacterial meningoencephalitis and meningomyelitis, NEC
- G04.3Acute necrotizing hemorrhagic encephalopathycategory
- G04.8Other encephalitis, myelitis and encephalomyelitiscategory
- G04.9Encephalitis, myelitis and encephalomyelitis, unspecifiedcategory
Where this code sits
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ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.