G31.8
Other specified degenerative diseases of nervous system
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 9 never code together
G00-G99chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 7
G31code
Use additional code
- code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:G31.0-G31.83G31.85-G31.9
- dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)F02.84F02.A4F02.B4F02.C4
- dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)F02.81-F02.A1-F02.B1-F02.C1-
- dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)F02.83F02.A3F02.B3F02.C3
- dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)F02.82F02.A2F02.B2F02.C2
- dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)F02.80F02.A0F02.B0F02.C0
- mild neurocognitive disorder due to known physiological condition (F06.7-)F06.7-
Index entries leading here filed at null
No alphabetic index entry points at this code.
Alongside this code 4 same parent — G31
Subordinate codes 9
G31.80 Leukodystrophy, unspecified G31.81 Alpers disease G31.82 Leigh's disease G31.83 Neurocognitive disorder with Lewy bodies G31.84 Mild cognitive impairment of uncertain or unknown etiology G31.85 Corticobasal degeneration G31.86 Alexander disease G31.87 Primary progressive apraxia of speech G31.89 Other specified degenerative diseases of nervous system
Medications 3
693 Central Nervous System Diseases drugs 16 Autonomic Nervous System Diseases drugs 80 Central Nervous System Infections drugs
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.