G31.83 Neurocognitive disorder with Lewy bodies

Billable ICD-10-CM code, FY2026.

Applicable to

• Lewy body dementia
• Lewy body disease

Use additional code

• code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-)

Applies from G31 Other degenerative diseases of nervous system, not elsewhere classified

Excludes2 (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-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 127 — Dementia, Mild or Unspecified
• RxHCC V08: HCC 112 — Dementia, Except Alzheimer's Disease
• ESRD V24: HCC 52

MS-DRG index

Defines the logic of DRG(s) 056-057 in MDC 01.

Approximate ICD-9-CM (GEMs)

• 331.82 Dementia with lewy bodies

Code annotations containing back-references to G31.83

Back-references to G31.83

• Code First: F02 Dementia in other diseases classified elsewhere ("neurocognitive disorder with Lewy bodies (G31.83)")
• Code First: F06.7 Mild neurocognitive disorder due to known physiological condition ("Neurocognitive disorder with Lewy bodies (G31.83)")
• Type 1 Excludes: G21 Secondary parkinsonism ("neurocognitive disorder with Lewy bodies (G31.83)")
• Use Additional: G31 Other degenerative diseases of nervous system, not elsewhere classified ("code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:")

Diagnosis Index entries for G31.83

• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › with › Lewy bodies
• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › with › Lewy bodies › with behavioral disturbance
• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › Lewy body
• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › Lewy body › with behavioral disturbance
• Disease, diseased › Lewy body (dementia)
• Disease, diseased › Lewy body (dementia) › with behavioral disturbance
• Disorder (of) › neurocognitive › with Lewy bodies
• Lewy body (ies) (disease)

Nearby codes

• G31.2 Degeneration of nervous system due to alcohol
• G31.8 Other specified degenerative diseases of nervous system
• G31.80 Leukodystrophy, unspecified
• G31.81 Alpers disease
• G31.82 Leigh's disease
• G31.83 Neurocognitive disorder with Lewy bodies (this code)
• 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