G31.2 ICD-10-CM Code: Degeneration of nervous system due to alcohol
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Other degenerative diseases of the nervous system (G30-G32)
G31.2
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceDegeneration of nervous system due to alcohol
Permanent damage to the nervous system caused by chronic alcohol consumption, resulting in cognitive and neurological impairment.
Buddy Insight
Degeneration of the nervous system due to alcohol captures permanent neurological damage from chronic alcohol use, which is distinct from acute intoxication effects.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
MappedHCC 52
RAF 0.346
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 52
RAF 0.0
RXHCC
MappedHCC 112
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Alcoholic cerebellar ataxia
- Alcoholic cerebellar degeneration
- Alcoholic cerebral degeneration
- Alcoholic encephalopathy
- Dysfunction of the autonomic nervous system due to alcohol
Excludes 2
Official- Reye's syndrome (G93.7)
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G31.2 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G31.2 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G31.2 in this effective period.
Use Additional
Official- 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)
Code Also
Official- associated alcoholism (F10.-)
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is G31.2 an HCC code?
Yes. G31.2 maps to Dementia Without Complication under the V24 model but is not retained in V28.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work G31.2 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for G31.2
For G31.2to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G31.2 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
G31.2 is the ICD-10-CM diagnosis code for degeneration of nervous system due to alcohol. Permanent damage to the nervous system caused by chronic alcohol consumption, resulting in cognitive and neurological impairment. G31.2 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering other degenerative diseases of the nervous system (g30-g32).
Under the older CMS-HCC V24 model, G31.2 maps to Dementia Without Complication (HCC 52) with a community, non-dual, aged base RAF weight of 0.346. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Ensure alcohol use disorder is also coded separately (F10.x codes) to capture the complete clinical picture. Because G31.2 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G31.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure alcohol use disorder is also coded separately (F10.x codes) to capture the complete clinical picture
- •Document the timeline and severity of alcohol use to support medical necessity
Clinical Significance
Degeneration of the nervous system due to alcohol captures permanent neurological damage from chronic alcohol use, which is distinct from acute intoxication effects. This condition reflects a serious long-term consequence of substance use disorder that requires ongoing neurological management and substance use treatment. It represents significant comorbidity in the patient's overall health profile.
Documentation Requirements
- ✓Documentation of chronic alcohol use or alcohol use disorder as the cause of nervous system degeneration
- ✓Neurological examination findings showing cognitive or motor deficits attributed to alcohol
- ✓Neuroimaging showing alcohol-related brain changes (cerebellar atrophy, cortical atrophy)
- ✓Duration and severity of alcohol use history
- ✓Confirmation that the neurological damage is permanent/chronic rather than acute intoxication
- ✓Associated alcohol use disorder code (F10.x) should be documented
Code Also
- associated alcoholism (F10.-)
Commonly Confused Codes
- •F10.27: Alcohol dependence with alcohol-induced persisting dementia; use when dementia criteria are met in active dependence
- •F10.97: Alcohol use, unspecified with alcohol-induced persisting dementia; different code family for alcohol-related dementia
- •G31.1: Senile degeneration of brain; age-related rather than alcohol-related
- •G31.9: Degenerative disease of nervous system, unspecified; does not capture the alcohol etiology
- •G62.1: Alcoholic polyneuropathy; peripheral nerve damage from alcohol, not central nervous system