G04
Encephalitis, myelitis and encephalomyelitis
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 16 never code together
G04code
Excludes2
- acute transverse myelitis (G37.3)G37.3G37.3G37.3
- alcoholic encephalopathy (G31.2)G31.2G31.2G31.2
- multiple sclerosis (G35-)G35-G35-G35-
- myalgic encephalomyelitis (G93.32)G93.32G93.32G93.32
- subacute necrotizing myelitis (G37.4)G37.4G37.4G37.4
- toxic encephalitis (G92.8)G92.8G92.8G92.8
- toxic encephalopathy (G92.8)G92.8G92.8G92.8
G00-G99chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 3
G04code
Includes
- acute ascending myelitis
- meningoencephalitis
- meningomyelitis
Index entries leading here filed at null
No alphabetic index entry points at this code.
Subordinate codes 6
G04.0 Acute disseminated encephalitis and encephalomyelitis (ADEM) G04.1 Tropical spastic paraplegia G04.2 Bacterial meningoencephalitis and meningomyelitis, NEC G04.3 Acute necrotizing hemorrhagic encephalopathy G04.8 Other encephalitis, myelitis and encephalomyelitis G04.9 Encephalitis, myelitis and encephalomyelitis, unspecified
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.