Coding and coverage · ICD-10-CM

G05 Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

Not billable (header)Chapter 6

Report one of the more specific codes below.

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Codes under this one

  • G05.3 Encephalitis and encephalomyelitis in diseases classified elsewhere
  • G05.4 Myelitis in diseases classified elsewhere

Instructional notes

Chapter 6

Excludes2Not included here: the patient may have both; report both when both are present.
  • 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)

This code

Excludes1Not coded here: never report with this code, except when 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)
Code firstSequence the underlying condition first.
  • 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)

Chapter 6: Diseases of the nervous system · G00-G09 Inflammatory diseases of the central nervous system (G00-G09)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.