ICD-10 Code for Myelitis

The default ICD-10-CM 2027 code for myelitis (acute) (ascending) (childhood) (chronic) (descending) (diffuse) (disseminated) (idiopathic) (pressure) (progressive) (spinal cord) (subacute) is G04.91 – Myelitis, unspecified. More specific codes depend on the details documented, as listed in the official index (14 codes, 14 billable).

Main code: G04.91 – Myelitis, unspecified
Billable: Yes
See also: Encephalitis

Index entries for Myelitis

flaccid – G04.82
herpes simplex – B00.82
herpes zoster – B02.24
in diseases classified elsewhere – G05.4
necrotizing, subacute – G37.4
optic neuritis in – G36.0
postchickenpox – B01.12
postherpetic – B02.24
postimmunization – G04.02
postinfectious NEC – G04.89
postvaccinal – G04.02
specified NEC – G04.89
syphilitic (transverse) – A52.14
toxic – G92.9
transverse (in demyelinating diseases of central nervous system) – G37.3
tuberculous – A17.82
varicella – B01.12

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.