G31 Other degenerative diseases of nervous system, not elsewhere classified

Category / Non-billable header 16 subcodes

Block: Other degenerative diseases of the nervous system (G30-G32)

Excludes 2 (not included here)

  • Reye's syndrome (G93.7)

Use Additional Code

  • code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:
  • dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
  • dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
  • dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
  • dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
  • dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
  • mild neurocognitive disorder due to known physiological condition (F06.7-)

Subcodes

Each subcode links to a detail page with full clinical annotations.

Code Description Billable
G31..0 Frontotemporal dementia No
G31..01 Pick's disease Yes
G31..09 Other frontotemporal neurocognitive disorder Yes
G31..1 Senile degeneration of brain, not elsewhere classified Yes
G31..2 Degeneration of nervous system due to alcohol Yes
G31..8 Other specified degenerative diseases of nervous system No
G31..80 Leukodystrophy, unspecified Yes
G31..81 Alpers disease Yes
G31..82 Leigh's disease Yes
G31..83 Neurocognitive disorder with Lewy bodies Yes
G31..84 Mild cognitive impairment of uncertain or unknown etiology Yes
G31..85 Corticobasal degeneration Yes
G31..86 Alexander disease Yes
G31..87 Primary progressive apraxia of speech Yes
G31..89 Other specified degenerative diseases of nervous system Yes
G31..9 Degenerative disease of nervous system, unspecified Yes

Last reviewed: September 2026