G04 — Encephalitis, myelitis and encephalomyelitis
Is G04 billable?
No — G04 is a non-billable header code. G04 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 14 billable codes beneath G04.
Billable codes under this header
- G04.1Tropical spastic paraplegia
- G04.2Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified
- G04.00Acute disseminated encephalitis and encephalomyelitis, unspecified
- G04.01Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)
- G04.02Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis
- G04.30Acute necrotizing hemorrhagic encephalopathy, unspecified
- G04.31Postinfectious acute necrotizing hemorrhagic encephalopathy
- G04.32Postimmunization acute necrotizing hemorrhagic encephalopathy
- G04.39Other acute necrotizing hemorrhagic encephalopathy
- G04.81Other encephalitis and encephalomyelitis
- G04.82Acute flaccid myelitis
- G04.89Other myelitis
- G04.90Encephalitis and encephalomyelitis, unspecified
- G04.91Myelitis, unspecified
G04 at a glance
| Code | G04 |
|---|---|
| Description | Encephalitis, myelitis and encephalomyelitis |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with G04 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- encephalopathy NOS (G93.40)
Excludes2 — not included here
The conditions below are not part of G04, but a patient may have both at the same time. When documentation supports it, G04 and the excluded code may both be reported.
Includes
Conditions classified to G04.
- acute ascending myelitis
- meningoencephalitis
- meningomyelitis
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G04, but a patient may have both at the same time. When documentation supports it, G04 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
What codes fall under G04? (6)
- G04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)not billable
- G04.1Tropical spastic paraplegia
- G04.2Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified
- G04.3Acute necrotizing hemorrhagic encephalopathynot billable
- G04.8Other encephalitis, myelitis and encephalomyelitisnot billable
- G04.9Encephalitis, myelitis and encephalomyelitis, unspecifiednot billable
How long has G04 existed?
G04 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.