G04.9Header code — not billable
Encephalitis, myelitis and encephalomyelitis, unspecified
- Chapter
- 6. Diseases of the nervous system
- Category
- G04
- Effective date
- October 1, 2026
Related codes in category G04
G04Encephalitis, myelitis and encephalomyelitisG04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)G04.00Acute disseminated encephalitis and encephalomyelitis, unspYesG04.01Postinfect acute dissem encephalitis and encephalomyelitisYesG04.02Postimmun ac dissem encphlts, myelitis and encephalomyelitisYesG04.1Tropical spastic paraplegiaYesG04.2Bacterial meningoencephalitis and meningomyelitis, NECYesG04.3Acute necrotizing hemorrhagic encephalopathyG04.30Acute necrotizing hemorrhagic encephalopathy, unspecifiedYesG04.31Postinfectious acute necrotizing hemorrhagic encephalopathyYesG04.32Postimmun acute necrotizing hemorrhagic encephalopathyYesG04.39Other acute necrotizing hemorrhagic encephalopathyYes
Frequently asked questions
What is ICD-10 code G04.9?
G04.9 is an ICD-10-CM diagnosis code for Encephalitis, myelitis and encephalomyelitis, unspecified.
Is G04.9 a billable code?
No. G04.9 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is G04.9 in?
G04.9 falls under Chapter 6: Diseases of the nervous system.
When did G04.9 become effective?
G04.9 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to G04.9?
G04.9 belongs to category G04, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.