Is G04.01 a billable ICD-10-CM code?

Yes. G04.01 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does G04.01 sit in the tabular list?

Diseases of the nervous system (G00-G99), in the block Inflammatory diseases of the central nervous system (G00-G09).

What cannot be coded together with G04.01?

G04.01 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

G04.01

G04.01 — Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)

Billable / specific codeICD-10-CM

G04.01 is a billable, specific ICD-10-CM code for postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious adem). It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

post chickenpox encephalitis (B01.1)
post measles encephalitis (B05.0)
post measles myelitis (B05.1)

Other codes that can never be billed with G04.01

These codes carry an Excludes1 note pointing at G04.01. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G04.01 alone.

G36Other acute disseminated demyelination

Risk adjustment

G04.01 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

G04.01 is named in 8 Medicare coverage policies — 8 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

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

How G04.01 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G04.01.

Encephalitis›postinfectious NEC
Encephalomyelitis›postinfectious NEC
Leukoencephalitis›postinfectious
Encephalomyelitis›acute disseminated›infectious
Encephalomyelitis›acute disseminated›postinfectious
Encephalitis›acute›disseminated›infectious
Encephalitis›acute›disseminated›postinfectious
Meningoencephalomyelitis›acute NEC›disseminated›postinfectious

Related codes at this level

Codes that share G04.0. If G04.01 is not quite right, the correct code is usually one of these.

Questions about G04.01

Is G04.01 a billable ICD-10-CM code?: Yes. G04.01 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G04.01 sit in the tabular list?: Diseases of the nervous system (G00-G99), in the block Inflammatory diseases of the central nervous system (G00-G09).
What cannot be coded together with G04.01?: G04.01 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.