When is ICD-10 code G31 used?

Doctors, hospitals, and insurers may use ICD-10 code G31 when recording other degenerative diseases of nervous system, not elsewhere classified in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code G31 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code G31: Other degenerative diseases of nervous system, not elsewhere classified

Name: ICD-10 Code G31: Other degenerative diseases of nervous system, not elsewhere classified
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:06:50.274Z

G31 is an ICD-10 diagnosis entry used to group records related to Other degenerative diseases of nervous system, not elsewhere classified. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

When is it used?

May be used when a clinician documents other degenerative diseases of nervous system, not elsewhere classified in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

6Diseases of the nervous system (G00-G99)

block

G30-G32Other degenerative diseases of the nervous system

currentG30-G32

Official coding notes

Applicable to

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-)

Excludes2 (may code together if documented)

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-)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

NeurologistGeneral Physician

Sibling codes

G30Alzheimer's disease G32Other degenerative disorders of nervous system in diseases classified elsewhere

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

G31

Replacement codes

G31.1 — Senile degeneration of brain, not elsewhere classifiedG31.2 — Degeneration of nervous system due to alcoholG31.9 — Degenerative disease of nervous system, unspecified

Common synonyms

Other degenerative diseases of nervous system, not elsewhere classified

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.