G04.01 Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)
The ICD-10-CM code for Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM) is G04.01 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- G00-G09: Inflammatory diseases of the central nervous system (G00-G09)
- Category G04
- 19 codes (14 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to G04.01:
- Encephalomyelitis › postinfectious NEC
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › postinfectious NEC
- Leukoencephalitis › postinfectious
- Encephalomyelitis › acute disseminated › infectious
- Encephalomyelitis › acute disseminated › postinfectious
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › acute › disseminated › infectious
- Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › acute › disseminated › postinfectious
- Meningoencephalomyelitis › acute NEC (viral) › disseminated › postinfectious
U.S. Hospital Utilization
- An estimated 370 U.S. inpatient stays in 2023 included G04.01 among the documented diagnoses.
- 275 stays listed it as the principal diagnosis.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
Dominant/nondominant side (TOC entry)a. Dominant/nondominant side ................................................................................................. 45
Pain - Category G89 (TOC entry)b. Pain - Category G89.............................................................................................................. 45
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026