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G31.83

G31.83Neurocognitive disorder with Lewy bodies

Billable / specific codeICD-10-CM

G31.83 is a billable, specific ICD-10-CM code for neurocognitive disorder with lewy bodies. It is valid for submission on a claim.

Use additional code

Add a secondary code to capture the detail described below.

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

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Lewy body dementia
  • Lewy body disease

Other codes that can never be billed with G31.83

These codes carry an Excludes1 note pointing at G31.83. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G31.83 alone.

  • G21Secondary parkinsonism

Risk adjustment

G31.83 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 127 Dementia, Mild or Unspecified0.341 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

G31.83 is named in 12 Medicare coverage policies 10 listing it as supporting medical necessity, and 2 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52434Health and Behavior Assessment/Intervention – Medical Policy Articlenot covered
  • A56562Billing and Coding: Health and Behavior Assessment/Interventionnot covered
  • A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
  • A56756Billing and Coding: Home Health - Psychiatric Care

How G31.83 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G31.83.

  • Lewy body(ies) (disease)
  • DementiaLewy body
  • Disease, diseasedLewy body(dementia)
  • DementiaLewy bodywith behavioral disturbance
  • DementiawithLewy bodies
  • Disease, diseasedLewy bodywith behavioral disturbance
  • Disorderneurocognitivewith Lewy bodies
  • DementiawithLewy bodieswith behavioral disturbance

Related codes at this level

Codes that share G31.8. If G31.83 is not quite right, the correct code is usually one of these.

Questions about G31.83

Is G31.83 a billable ICD-10-CM code?
Yes. G31.83 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G31.83 sit in the tabular list?
Diseases of the nervous system (G00-G99), in the block Other degenerative diseases of the nervous system (G30-G32).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.