G05Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

G05 is the ICD-10-CM diagnosis code for encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere. It belongs to block G00-G09 (inflammatory diseases of the central nervous system) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: G05.3 (elsewhere) and G05.4 (elsewhere).

Don't report G05 together with the conditions in its Excludes1 note: 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) and 7 more.

Code 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) and 5 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.