G04
Non-Billable

Encephalitis, myelitis and encephalomyelitis

Non-Billable / Non-Specific Code

What is Encephalitis, myelitis and encephalomyelitis?

ICD-10-CM G04 is the diagnosis code for Encephalitis, myelitis and encephalomyelitis. This code falls under the section "Inflammatory diseases of the central nervous system" within Chapter 6 — Diseases of the nervous system (G00-G99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

⛔ Excludes1
â„šī¸ Excludes2

Coding Guidelines for G04

⛔ Type 1 Excludes (Never code together)

The following conditions should never be coded at the same time as G04. They are mutually exclusive:

  • encephalopathy NOS (G93.40)

â„šī¸ Type 2 Excludes (Code separately if applicable)

The following conditions are not included in G04. If the patient has both, code each condition separately:

  • acute transverse myelitis (G37.3)
  • alcoholic encephalopathy (G31.2)
  • multiple sclerosis (G35-)
  • myalgic encephalomyelitis (G93.32)
  • subacute necrotizing myelitis (G37.4)
  • toxic encephalitis (G92.8)
  • toxic encephalopathy (G92.8)

ICD-10-CM Code Hierarchy

Understanding where G04 sits in the ICD-10-CM classification helps ensure proper coding:

Current CodeG04 — Encephalitis, myelitis and encephalomyelitis
Sub-Codes 6 entries
G04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)Non-BillableG04.00Acute disseminated encephalitis and encephalomyelitis, unspecifiedBillableG04.01Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)BillableG04.02Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitisBillableG04.1Tropical spastic paraplegiaBillableG04.2Bacterial meningoencephalitis and meningomyelitis, not elsewhere classifiedBillableG04.3Acute necrotizing hemorrhagic encephalopathyNon-BillableG04.30Acute necrotizing hemorrhagic encephalopathy, unspecifiedBillableG04.31Postinfectious acute necrotizing hemorrhagic encephalopathyBillableG04.32Postimmunization acute necrotizing hemorrhagic encephalopathyBillableG04.39Other acute necrotizing hemorrhagic encephalopathyBillableG04.8Other encephalitis, myelitis and encephalomyelitisNon-BillableG04.81Other encephalitis and encephalomyelitisBillableG04.82Acute flaccid myelitisBillableG04.89Other myelitisBillableG04.9Encephalitis, myelitis and encephalomyelitis, unspecifiedNon-BillableG04.90Encephalitis and encephalomyelitis, unspecifiedBillableG04.91Myelitis, unspecifiedBillable
Related Codes

Frequently Asked Questions

Is G04 a billable ICD-10-CM code?

No, G04 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does G04 mean?

G04 is the ICD-10-CM diagnosis code for "Encephalitis, myelitis and encephalomyelitis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What section is G04 in?

G04 is located in Section G00-G09 — "Inflammatory diseases of the central nervous system" within Chapter 6 of the ICD-10-CM Tabular List.

What are the sub-codes of G04?

G04 has 6 sub-code(s) that provide more specific detail: G04.0, G04.1, G04.2, G04.3, G04.8 and more.

When should I use G04?

Use G04 when the patients documented diagnosis matches "Encephalitis, myelitis and encephalomyelitis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Encephalitis, myelitis and encephalomyelitis?

The ICD-10-CM code for Encephalitis, myelitis and encephalomyelitis is G04.

Can G04 be used for primary diagnosis?

No, G04 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is G04 in?

G04 is in Chapter 6 of the ICD-10-CM Tabular List.

What conditions are excluded from G04?

Type 1 Excludes for G04 include: encephalopathy NOS (G93.40).

Is G04 valid for 2026?

Yes, G04 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousG03.9Meningitis, unspecifiedNext →G04.0Acute disseminated encephalitis and encephalomyelitis (ADEM)
Code Details
G04
Encephalitis, myelitis and encephalomyelitis
Non-Billable / Non-Specific Code
6 — Diseases of the nervous system (G00-G99)
G00-G09 — Inflammatory diseases of the central nervous system
2026 ICD-10-CM