G31 – Other degenerative diseases of nervous system, not elsewhere classified
ICD-10-CM 2027 diagnosis code · Other degenerative diseases of the nervous system
ICD-10-CM code
G31
- Code
G31(claims format:G31)- Description
- Other degenerative diseases of nervous system, not elsewhere classified
- Short description
- Oth degenerative diseases of nervous system, NEC
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 6. Diseases of the nervous system (G00-G99)
- Block
- G30-G32 Other degenerative diseases of the nervous system
Billable codes under G31
G31 is a header code and cannot be used on claims. Choose the most specific code:
- G31.0 – Frontotemporal dementiaHeader (more codes below)
- G31.1 – Senile degeneration of brain, not elsewhere classifiedBillable
- G31.2 – Degeneration of nervous system due to alcoholBillable
- G31.8 – Other specified degenerative diseases of nervous systemHeader (more codes below)
- G31.9 – Degenerative disease of nervous system, unspecifiedBillable
Notes for G31
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-)
Frequently asked questions
What is ICD-10 code G31?
G31 is the ICD-10-CM code for other degenerative diseases of nervous system, not elsewhere classified, in the block G30-G32 (Other degenerative diseases of the nervous system).
Is G31 a billable code?
No. G31 is a header code with more specific child codes; report one of the billable codes listed above.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.