ICD-10-CM
ICD-10 code for Myelitis: G04.91
The ICD-10-CM index points "Myelitis" to G04.91, Myelitis, unspecified. G04.91 is a billable code.
Source: CDC ICD-10-CM FY2027 Alphabetic Index file dated June 16, 2026. Publisher page
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Index subterms
A header groups codes and is not billed. A billable code is one you can report. Listed second marks a billable manifestation code (its CDC title says it is "classified elsewhere"): code the underlying disease or condition first, then this code.
- G04.82flaccid, Acute flaccid myelitisBillable
- B00.82herpes simplex, Herpes simplex myelitisBillable
- B02.24herpes zoster, Postherpetic myelitisBillable
- G05.4in diseases classified elsewhere, Myelitis in diseases classified elsewhereListed second
- G37.4necrotizing, subacute, Subacute necrotizing myelitis of central nervous systemBillable
- G36.0optic neuritis in, Neuromyelitis optica [Devic]Billable
- B01.12postchickenpox, Varicella myelitisBillable
- B02.24postherpetic, Postherpetic myelitisBillable
- G04.02postimmunization, Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitisBillable
- G04.89postinfectious NEC, Other myelitisBillable
- G04.02postvaccinal, Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitisBillable
- G04.89specified NEC, Other myelitisBillable
- A52.14syphilitic (transverse), Late syphilitic encephalitisBillable
- G92.9toxic, Unspecified toxic encephalopathyBillable
- G37.3transverse (in demyelinating diseases of central nervous system), Acute transverse myelitis in demyelinating disease of central nervous systemBillable
- A17.82tuberculous, Tuberculous meningoencephalitisBillable
- B01.12varicella, Varicella myelitisBillable
More specific codes in G04
A header groups codes and is not billed. A billable code is one you can report.
- G04Encephalitis, myelitis and encephalomyelitisHeader
- G04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)Header
- G04.00Acute disseminated encephalitis and encephalomyelitis, unspecifiedBillable
- G04.01Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)Billable
- G04.02Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitisBillable
- G04.1Tropical spastic paraplegiaBillable
- G04.2Bacterial meningoencephalitis and meningomyelitis, not elsewhere classifiedBillable
- G04.3Acute necrotizing hemorrhagic encephalopathyHeader
- G04.30Acute necrotizing hemorrhagic encephalopathy, unspecifiedBillable
- G04.31Postinfectious acute necrotizing hemorrhagic encephalopathyBillable
- G04.32Postimmunization acute necrotizing hemorrhagic encephalopathyBillable
- G04.39Other acute necrotizing hemorrhagic encephalopathyBillable
- G04.8Other encephalitis, myelitis and encephalomyelitisHeader
- G04.81Other encephalitis and encephalomyelitisBillable
- G04.82Acute flaccid myelitisBillable
- G04.89Other myelitisBillable
- G04.9Encephalitis, myelitis and encephalomyelitis, unspecifiedHeader
- G04.90Encephalitis and encephalomyelitis, unspecifiedBillable
- G04.91Myelitis, unspecifiedBillable
Excludes1
Excludes1 means these codes are not reported together.
From G04. A note on a category applies to every code under it.
Excludes2
Excludes2 means the other condition can be reported with this one when both are documented.
From G04. A note on a category applies to every code under it.
Related conditions
Related pages
- G04.91 code detailsNotes, nearby codes, CMS-HCC group
- Category G04Every code under it
- Chapter 6Diseases of the nervous system
- ICD-10 codes by conditionA to Z
- Check a list of ICD-10 codes
- Denial code CO-11Diagnosis does not support the procedure
- Denial code CO-146Diagnosis invalid for the date of service
- HCPCS Level II code lookup
Questions
What is the ICD-10 code for Myelitis?
The ICD-10-CM index points "Myelitis" to G04.91, Myelitis, unspecified. G04.91 is a billable code.
Is G04.91 billable?
Yes. G04.91 is a billable code in the FY2027 ICD-10-CM file. Use a more specific code when the record documents one.
What documentation notes apply to G04.91?
The CDC tabular list gives 1 Excludes1 note (not coded together), 7 Excludes2 notes (may be coded together when both are documented) for G04.91 and the categories above it. They are listed on this page.
What chapter is G04.91 in?
Chapter 6. Diseases of the nervous system.
When do ICD-10-CM codes change?
Every October 1, with the new fiscal year file. Some years add April 1 updates. This page uses the FY2027 file, effective October 1, 2026.