Is ICD-10-CM code G31 billable?

No, G31 (Other degenerative diseases of nervous system, not elsewhere classified) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code G31 belong to?

G31 belongs to Chapter 6 of the ICD-10-CM tabular list: G00–G99 (Diseases of the Nervous System).

G31Non-billable

Other degenerative diseases of nervous system, not elsewhere classified

Diseases of the Nervous System·Other degenerative diseases of the nervous system (G30-G32)·category·FY 2026

Use a more specific code (3 billable, 2 non-billable)

G31.0Frontotemporal dementiahas subcodes G31.1Senile degeneration of brain, not elsewhere classified G31.2Degeneration of nervous system due to alcohol G31.8Other specified degenerative diseases of nervous systemhas subcodes G31.9Degenerative disease of nervous system, unspecified

CH6 Parent Instructions

Excludes2(Not included here. Code separately if applicable.)

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)

Instructional Notes

Excludes2(Not included here. Code separately if applicable.)

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-)

Clinical Hierarchy

BillableHas subcodes

CH6Diseases of the nervous system (G00-G99)

G30-G32Other degenerative diseases of the nervous system (G30-G32)

G31Other degenerative diseases of nervous system, not elsewhere classifiedNot billable

G31.0Frontotemporal dementiaSubcodes

G31.1Senile degeneration of brain, not elsewhere classifiedBillable

G31.2Degeneration of nervous system due to alcoholBillable

G31.8Other specified degenerative diseases of nervous systemSubcodes

G31.9Degenerative disease of nervous system, unspecifiedBillable

MS-DRG Classification

2026

No direct MS-DRG triggers identified.