G31 — Other degenerative diseases of nervous system, not elsewhere classified
Is G31 billable?
No — G31 is a non-billable header code. G31 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 14 billable codes beneath G31.
Billable codes under this header
- G31.1Senile degeneration of brain, not elsewhere classified
- G31.2Degeneration of nervous system due to alcohol
- G31.9Degenerative disease of nervous system, unspecified
- G31.01Pick's disease
- G31.09Other frontotemporal neurocognitive disorder
- G31.80Leukodystrophy, unspecified
- G31.81Alpers disease
- G31.82Leigh's disease
- G31.83Neurocognitive disorder with Lewy bodies
- G31.84Mild cognitive impairment of uncertain or unknown etiology
- G31.85Corticobasal degeneration
- G31.86Alexander disease
- G31.87Primary progressive apraxia of speech
- G31.89Other specified degenerative diseases of nervous system
G31 at a glance
| Code | G31 |
|---|---|
| Description | Other degenerative diseases of nervous system, not elsewhere classified |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Use additional code
Report an additional code alongside G31 to fully describe the condition. G31 is sequenced first.
- 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 — not included here
The conditions below are not part of G31, but a patient may have both at the same time. When documentation supports it, G31 and the excluded code may both be reported.
- Reye's syndrome (G93.7)
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G31, but a patient may have both at the same time. When documentation supports it, G31 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
What codes fall under G31? (5)
How long has G31 existed?
G31 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.