Coding and coverage · ICD-10-CM
G31.8 Other specified degenerative diseases of nervous system
Report one of the more specific codes below.
Codes under this one
- G31.80 Leukodystrophy, unspecified
- G31.81 Alpers disease
- G31.82 Leigh's disease
- G31.83 Neurocognitive disorder with Lewy bodies
- G31.84 Mild cognitive impairment of uncertain or unknown etiology
- G31.85 Corticobasal degeneration
- G31.86 Alexander disease
- G31.87 Primary progressive apraxia of speech
- G31.89 Other specified degenerative diseases of nervous system
Instructional notes
Chapter 6
Excludes2Not included here: the patient may have both; report both when both are present.
- 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)
G31
Excludes2Not included here: the patient may have both; report both when both are present.
- Reye's syndrome (G93.7)
Use additional codeAdd a second code for the full picture.
- 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-)
Chapter 6: Diseases of the nervous system · G30-G32 Other degenerative diseases of the nervous system (G30-G32)
Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.
Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.