| G00 | Bacterial meningitis, not elsewhere classified |
| G00.0 | Hemophilus meningitis |
| G00.1 | Pneumococcal meningitis |
| G00.2 | Streptococcal meningitis |
| G00.3 | Staphylococcal meningitis |
| G00.8 | Other bacterial meningitis |
| G00.9 | Bacterial meningitis, unspecified |
| G01 | Meningitis in bacterial diseases classified elsewhere |
| G02 | Meningitis in other infectious and parasitic diseases classified elsewhere |
| G03 | Meningitis due to other and unspecified causes |
| G03.0 | Nonpyogenic meningitis |
| G03.1 | Chronic meningitis |
| G03.2 | Benign recurrent meningitis [Mollaret] |
| G03.8 | Meningitis due to other specified causes |
| G03.9 | Meningitis, unspecified |
| G04 | Encephalitis, myelitis and encephalomyelitis |
| 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 |
| 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 |
| G04.8 | Other encephalitis, myelitis and encephalomyelitis |
| G04.81 | Other encephalitis and encephalomyelitis |
| G04.89 | Other myelitis |
| G04.9 | Encephalitis, myelitis and encephalomyelitis, unspecified |
| G04.90 | Encephalitis and encephalomyelitis, unspecified |
| G04.91 | Myelitis, unspecified |
| G05 | Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere |
| G05.3 | Encephalitis and encephalomyelitis in diseases classified elsewhere |
| G05.4 | Myelitis in diseases classified elsewhere |
| G06 | Intracranial and intraspinal abscess and granuloma |
| G06.0 | Intracranial abscess and granuloma |
| G06.1 | Intraspinal abscess and granuloma |
| G06.2 | Extradural and subdural abscess, unspecified |
| G07 | Intracranial and intraspinal abscess and granuloma in diseases classified elsewhere |
| G08 | Intracranial and intraspinal phlebitis and thrombophlebitis |
| G09 | Sequelae of inflammatory diseases of central nervous system |