G31.89
Other specified degenerative diseases of nervous system
G31.89 (also written G3189) is a billable ICD-10-CM diagnosis code for other specified degenerative diseases of nervous system. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 14 codes in category G31 (Other degenerative diseases of nervous system, not elsewhere classified). The Alphabetic Index lists it under 11 entries. Its coding notes include a Use additional code instruction and 9 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
- 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. Both codes may be reported if the patient has both conditions.
- Reye's syndrome (G93.7)
Also from chapter/block level (8 notes)
- 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)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Neuro Rehabilitation clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026IPF Primary
IPF MS-DRG adjustment. A principal diagnosis of this code groups to one of these MS-DRGs. Which one depends on other facts of the stay, so the factor is a range:
| MS-DRG | Description | Factor |
|---|---|---|
| 056 | Degenerative nervous system disorders w MCC | 1.12 |
| 057 | Degenerative nervous system disorders w/o MCC | 1.11 |
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 11 entries
- Degeneration, degenerative, brain (cortical) (progressive), childhood, specified NEC
- Degeneration, degenerative, brain (cortical) (progressive), cystic
- Degeneration, degenerative, cortical (cerebellar) (parenchymatous)
- Degeneration, degenerative, nervous system, fatty
- Degeneration, degenerative, nervous system, specified NEC
- Degeneration, degenerative, spinal (cord)
- Degeneration, degenerative, spinal (cord), familial NEC
- Degeneration, degenerative, spinal (cord), fatty
- Dystrophy, dystrophia, infantile neuraxonal
- Seitelberger's syndrome (infantile neuraxonal dystrophy)
- Syndrome, Seitelberger's