2027 ICD-10-CM Diagnosis Code G31Other degenerative diseases of nervous system, not elsewhere classified

ICD-10-CM Codes›G00–G99›G30-G32›G31

ICD-10-CM G31
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G31 is a non-billable ICD-10-CM category code for other degenerative diseases of nervous system, not elsewhere classified, so it cannot be submitted on claims. Use a more specific code from this category instead, such as G31.01, G31.09, G31.1, and G31.2.

Code Identity

ICD-10-CM Code
G31
Billable Status
No — Non-Billable Category
Code Describes
Other degenerative diseases of nervous system, not elsewhere classified
Short Description
Oth degenerative diseases of nervous system, NEC
Chapter
G30-G32
Other degenerative diseases of the nervous system

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG30-G32Other degenerative diseases of the nervous system
CategoryG31Other degenerative diseases of nervous system, not elsewhere classified
This CodeG31Other degenerative diseases of nervous system, not elsewhere classified

Specific Coding for Oth degenerative diseases of nervous system, NECOverview

Non-specific codes like G31 require more characters. Use one of these billable codes instead:

  • G31.0 for Frontotemporal dementia

  • Use G31.01 for Pick's disease

  • Use G31.09 for Other frontotemporal neurocognitive disorder

  • Use G31.1 for Senile degeneration of brain, not elsewhere classified

  • Use G31.2 for Degeneration of nervous system due to alcohol

  • G31.8 for Other specified degenerative diseases of nervous system

  • Use G31.80 for Leukodystrophy, unspecified

  • Use G31.81 for Alpers disease

  • Use G31.82 for Leigh's disease

  • Use G31.83 for Neurocognitive disorder with Lewy bodies

  • Use G31.84 for Mild cognitive impairment of uncertain or unknown etiology

  • Use G31.85 for Corticobasal degeneration

  • Use G31.86 for Alexander disease

  • Use G31.87 for Primary progressive apraxia of speech

  • Use G31.89 for Other specified degenerative diseases of nervous system

  • Use G31.9 for Degenerative disease of nervous system, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G31: its own notes plus those printed at Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On G31 itself
From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • 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)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Patient EducationClinical

Degenerative Nerve Diseases

Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and viruses.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G31Overview

Is G31 a billable code?

No. This is a category header that groups the codes for other degenerative diseases of nervous system, not elsewhere classified, and headers cannot be submitted on claims. Claims for other degenerative diseases of nervous system, not elsewhere classified need a more specific code from this category, such as G31.01, G31.09, and G31.1.

Does G31 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: 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); and 1 more listed in the Instructional Notes section. The additional code is reported after G31.