G04.02: Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis
G04.02 is a billable, specific ICD-10-CM code for postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis. It is valid for submission on a claim.
Check G04.02 with the rest of the claim: free scrubberUse additional code
Add a secondary code to capture the detail described below.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Encephalitis, post immunization
- Encephalomyelitis, post immunization
Excludes1 inherited from the categories above G04.02
A category’s note binds every code beneath it.
Written on G04.0: Acute disseminated encephalitis and encephalomyelitis (ADEM)
Excludes2 inherited from the categories above G04.02
Not part of this code, but both may be coded when both are present.
Other codes that can never be billed with G04.02
Their own Excludes1 notes name this code, so the conflict is not listed above.
- G03Meningitis due to other and unspecified causes
Risk adjustment
No CMS-HCC V28 category: this code does not change a RAF score.
Medicare coverage
G04.02 is named in 8 Medicare coverage policies: 8 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.
- A56551Billing and Coding: Visual Fields Testing
- A56771Billing and Coding: Special Electroencephalography
- A56799Billing and Coding: Visual Fields Testing
- A57204Billing and Coding: MRI and CT Scans of the Head and Neck
Alphabetic index entries that lead here
- Encephalitis›following vaccination or other immunization procedure
- Encephalitis›postimmunization
- Encephalitis›postvaccinal
- Encephalomyelitis›postvaccinal
- Leukoencephalopathy›postimmunization and postvaccinal
- Meningoencephalomyelitis›postimmunization or postvaccination
- Myelitis›postimmunization
- Myelitis›postvaccinal
- Complication›vaccination›encephalitis or encephalomyelitis
- Complication›vaccination›myelitis
- Encephalitis›due to›smallpox inoculation
- Encephalomyelitis›acute disseminated›postimmunization
Code history
Unchanged in every release from FY2024 to FY2027.