ICD10BillableValid for clinical use

ICD-10 Code G04.81: Other encephalitis and encephalomyelitis

G04.81 is a billable ICD-10 diagnosis code used to classify Other encephalitis and encephalomyelitis in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

When is it used?

  • May be used when a clinician documents other encephalitis and encephalomyelitis in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
6Diseases of the nervous system (G00-G99)
block
G00-G09Inflammatory diseases of the central nervous system
category
G04Encephalitis, myelitis and encephalomyelitis
category
G04.8Other encephalitis, myelitis and encephalomyelitis
currentG04.8

Official coding notes

Inclusion terms
  • Noninfectious acute disseminated encephalomyelitis (noninfectious ADEM)

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

NeurologistGeneral Physician

Coverage-related procedures and services

CPT 87483high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); CENTRAL NERVOUS SYSTEM PATHOGEN (EG, NEISSERIA MENINGITIDIS, STREPTOCOCCUS PNEUMONIAE, LISTERIA, HAEMOPHILUS INFLUENZAE, E. COLI, STREPTOCOCCUS AGALACTIAE, ENTEROVIRUS, HUMAN PARECHOVIRUS, HERPES SIMPLEX VIRUS TYPE 1 AND 2, HUMAN HERPESVIRUS 6, CYTOMEGALOVIRUS, VARICELLA ZOSTER VIRUS, CRYPTOCOCCUS), INCLUDES MULTIPLEX REVERSE TRANSCRIPTION, WHEN PERFORMED, AND MULTIPLEX AMPLIFIED PROBE TECHNIQUE, MULTIPLE TYPES OR SUBTYPES, 12-25 TARGETS
Source: CMS coverage guidance
CPT 0595Uhigh
INFECTIOUS DISEASE (TROPICAL FEVER PATHOGENS), VECTOR-BORNE AND ZOONOTIC PATHOGENS, INCLUDING 2 VIRUSES (CHIKUNGUNYA VIRUS AND DENGUE VIRUS SEROTYPES 1, 2, 3, AND 4), 1 BACTERIUM (LEPTOSPIRA SPECIES), AND 1 PARASITE WITH SPECIES DIFFERENTIATION (PLASMODIUM SPECIES, PLASMODIUM FALCIPARUM, AND PLASMODIUM VIVAX/OVALE), REAL-TIME RT-PCR, WHOLE BLOOD, EACH PATHOGEN REPORTED AS DETECTED OR NOT DETECTED
Source: CMS coverage guidance
CPT 87999high
UNLISTED MICROBIOLOGY PROCEDURE
Source: CMS coverage guidance
HCPCS J1552high
INJECTION, IMMUNE GLOBULIN (ALYGLO), 500 MG
Source: CMS coverage guidance
HCPCS J1554high
INJECTION, IMMUNE GLOBULIN (ASCENIV), 500 MG
Source: CMS coverage guidance
HCPCS J1556high
INJECTION, IMMUNE GLOBULIN (BIVIGAM), 500 MG
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Other encephalitis and encephalomyelitis

Frequently asked questions

Code details

CodeG04.81
SystemICD10
Display nameOther encephalitis and encephalomyelitis
ChapterDiseases of the nervous system (G00-G99)
BlockInflammatory diseases of the central nervous system

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Encephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)Encephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)Encephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)Encephalitis(chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)EncephalomyelitisEncephalomyelitisLeukoencephalitisMeningoencephalitisRasmussen encephalitisSyndrome

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code G04.81 for Other encephalitis and encephalomyelitis | HealthAssure