G04.2 Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applies from G04 Encephalitis, myelitis and encephalomyelitis

Includes

• acute ascending myelitis
• meningoencephalitis
• meningomyelitis

Excludes1 (never code together)

• encephalopathy NOS (G93.40)

Excludes2 (not included here)

• 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)

MS-DRG index

Defines the logic of DRG(s) 023-024 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 320.9 Meningitis due to unspecified bacterium (approximate)

Code annotations containing back-references to G04.2

Back-references to G04.2

• Type 1 Excludes: G00 Bacterial meningitis, not elsewhere classified ("bacterial meningoencephalitis (G04.2)")
• Type 1 Excludes: G00 Bacterial meningitis, not elsewhere classified ("bacterial meningomyelitis (G04.2)")

Back-references to G04

• Type 1 Excludes: G03 Meningitis due to other and unspecified causes ("meningoencephalitis (G04.-)")
• Type 1 Excludes: G03 Meningitis due to other and unspecified causes ("meningomyelitis (G04.-)")
• Type 2 Excludes: G95 Other and unspecified diseases of spinal cord ("myelitis (G04.-)")

Diagnosis Index entries for G04.2

• Meningoencephalitis › bacterial NEC
• Meningoencephalitis › pneumococcal
• Meningoencephalitis › staphylococcal
• Meningoencephalitis › streptococcal
• Meningomyelitis › bacterial NEC

Nearby codes

• G04.0 Acute disseminated encephalitis and encephalomyelitis (ADEM)
• G04.00 Acute disseminated encephalitis and encephalomyelitis, unspecified
• G04.01 Postinfectious acute disseminated encephalitis and encephalomyelitis (postinfectious ADEM)
• G04.02 Postimmunization acute disseminated encephalitis, myelitis and encephalomyelitis
• G04.1 Tropical spastic paraplegia
• G04.2 Bacterial meningoencephalitis and meningomyelitis, not elsewhere classified (this code)
• G04.3 Acute necrotizing hemorrhagic encephalopathy
• G04.30 Acute necrotizing hemorrhagic encephalopathy, unspecified
• G04.31 Postinfectious acute necrotizing hemorrhagic encephalopathy
• G04.32 Postimmunization acute necrotizing hemorrhagic encephalopathy
• G04.39 Other acute necrotizing hemorrhagic encephalopathy