2027 ICD-10-CM Diagnosis Code G05Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

ICD-10-CM Codes›G00–G99›G00-G09›G05

ICD-10-CM G05
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G05 is a non-billable ICD-10-CM category code for encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere, so it cannot be submitted on claims. Use a more specific code from this category instead, such as G05.3 and G05.4.

Code Identity

ICD-10-CM Code
G05
Billable Status
No — Non-Billable Category
Code Describes
Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere
Short Description
Encphlts, myelitis & encephalomyelitis in dis classd elswhr
Chapter
G00-G09
Inflammatory diseases of the central nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG00-G09Inflammatory diseases of the central nervous system
CategoryG05Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere
This CodeG05Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

Specific Coding for Encphlts, myelitis & encephalomyelitis in dis classd elswhrOverview

Non-specific codes like G05 require more characters. Use one of these billable codes instead:

  • Use G05.3 for Encephalitis and encephalomyelitis in diseases classified elsewhere

  • Use G05.4 for Myelitis in diseases classified elsewhere

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G05: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

  • adenoviral encephalitis, myelitis and encephalomyelitis (A85.1)
  • encephalitis, myelitis and encephalomyelitis (in) measles (B05.0)
  • enteroviral encephalitis, myelitis and encephalomyelitis (A85.0)
  • herpesviral [herpes simplex] encephalitis, myelitis and encephalomyelitis (B00.4)
  • listerial encephalitis, myelitis and encephalomyelitis (A32.12)
  • meningococcal encephalitis, myelitis and encephalomyelitis (A39.81)
  • mumps encephalitis, myelitis and encephalomyelitis (B26.2)
  • postchickenpox encephalitis, myelitis and encephalomyelitis (B01.1-)
  • rubella encephalitis, myelitis and encephalomyelitis (B06.01)
  • toxoplasmosis encephalitis, myelitis and encephalomyelitis (B58.2)
  • zoster encephalitis, myelitis and encephalomyelitis (B02.0)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • 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)

Code First

The underlying condition named in the note is sequenced before this code.

  • underlying disease, such as:
  • congenital toxoplasmosis encephalitis, myelitis and encephalomyelitis (P37.1)
  • cytomegaloviral encephalitis, myelitis and encephalomyelitis (B25.8)
  • encephalitis, myelitis and encephalomyelitis (in) systemic lupus erythematosus (M32.19)
  • eosinophilic meningoencephalitis (B83.2)
  • human immunodeficiency virus [HIV] disease (B20)
  • poliovirus (A80.-)
  • suppurative otitis media (H66.01-H66.4)
  • systemic lupus erythematosus (M32.19)
  • trichinellosis (B75)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G05, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming G05: they are not reported together with it, unless the two conditions are unrelated.

  • G01 Meningitis in bacterial diseases classified elsewhere
    meningoencephalitis and meningomyelitis in bacterial diseases classified elsewhere (G05)
  • G02 Meningitis in other infectious and parasitic diseases classified elsewhere
    meningoencephalitis and meningomyelitis in other infectious and parasitic diseases classified elsewhere (G05)

Notes 1

These notes mention G05.

  • G09 Sequelae of inflammatory diseases of central nervous system
    Category G09 is to be used to indicate conditions whose primary classification is to G00-G08 as the cause of sequelae, themselves classifiable elsewhere. The 'sequelae' include conditions specified as residuals. names G00-G08, which includes this code

Patient EducationClinical

Encephalitis

Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death.

The full article covers:

  • What is encephalitis?
  • What causes encephalitis?
  • Who is more likely to get encephalitis?
  • What are the symptoms of encephalitis?
  • How is encephalitis diagnosed?
  • What are the treatments for encephalitis?
  • Can encephalitis be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G05Overview

Is G05 a billable code?

No. This is a category header that groups the codes for encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere, and headers cannot be submitted on claims. Claims for encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere need a more specific code from this category, such as G05.3 and G05.4.

Can G05 be reported with A85.1?

Not as a rule. The Excludes1 note on G05 lists "adenoviral encephalitis, myelitis and encephalomyelitis (A85.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is coded first with G05?

The Code First note reads: underlying disease, such as: congenital toxoplasmosis encephalitis, myelitis and encephalomyelitis (P37.1); cytomegaloviral encephalitis, myelitis and encephalomyelitis (B25.8); encephalitis, myelitis and encephalomyelitis (in) systemic lupus erythematosus (M32.19); eosinophilic meningoencephalitis (B83.2); human immunodeficiency virus [HIV] disease (B20); and 4 more listed in the Instructional Notes section. When one of these applies, it is sequenced before G05.