ICD-10 Code for Myelitis
Also indexed as (acute) (ascending) (childhood) (chronic) (descending) (diffuse) (disseminated) (idiopathic) (pressure) (progressive) (spinal cord) (subacute)
The ICD-10-CM code for myelitis is G04.91 — Myelitis, unspecified. This is the code the Alphabetic Index gives for myelitis with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
G04.91 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which myelitis code should you use?
The Alphabetic Index lists 14 codes under Myelitis. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| flaccid | G04.82 | Acute flaccid myelitis | |
| herpes simplex | B00.82 | Herpes simplex myelitis | |
| herpes zoster | B02.24 | Postherpetic myelitis | |
| in diseases classified elsewhere | G05.4 | Myelitis in diseases classified elsewhere | |
| necrotizing, subacute | G37.4 | Subacute necrotizing myelitis of central nervous system | |
| optic neuritis in | G36.0 | Neuromyelitis optica [Devic] | |
| postchickenpox | B01.12 | Varicella myelitis | |
| postherpetic | B02.24 | Postherpetic myelitis | |
| postimmunization | G04.02 | Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis | |
| postinfectious NEC | G04.89 | Other myelitis | |
| postvaccinal | G04.02 | Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis | |
| specified NEC | G04.89 | Other myelitis | |
| syphilitic | A52.14 | Late syphilitic encephalitis | |
| toxic | G92.9 | Unspecified toxic encephalopathy | |
| transverse | G37.3 | Acute transverse myelitis in demyelinating disease of central nervous system | |
| tuberculous | A17.82 | Tuberculous meningoencephalitis | |
| varicella | B01.12 | Varicella myelitis |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources