ICD-10-CM 2027
ICD-10 code for lewy body dementia)
From the official ICD-10-CM alphabetic index entry “Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › Lewy body”. Page updated September 29, 2026.
About coding lewy body dementia)
The ICD-10-CM code for lewy body dementia) is G31.83 (Neurocognitive disorder with Lewy bodies). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on G31.83.
Within G31.8 (other specified degenerative diseases of nervous system), G31.83 is specifically for neurocognitive disorder with Lewy bodies. Related codes cover leukodystrophy, unspecified (G31.80), Alpers disease (G31.81), Leigh's disease (G31.82), mild cognitive impairment of uncertain or unknown etiology (G31.84), Corticobasal degeneration (G31.85), Alexander disease (G31.86), primary progressive apraxia of speech (G31.87) and other specified degenerative diseases of nervous system (G31.89).
Use an additional code, if applicable, to identify mild neurocognitive disorders due to known physiological condition (F06.7-). Use an additional 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) and 1 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific lewy body dementia) codes (official index)
- with behavioral disturbance G31.83 — Neurocognitive disorder with Lewy bodies
Common questions about lewy body dementia) ICD-10 codes
What is the ICD-10 code for lewy body dementia)?
- G31.83 — Neurocognitive disorder with Lewy bodies. More specific codes apply when the documentation supports them: G31.83.
Is G31.83 billable?
- Yes. G31.83 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G31.83 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G31.83 as a principal diagnosis.
Is G31.83 a CC or MCC?
- No. G31.83 is neither a CC nor an MCC under MS-DRG v44.0.