FY2027 ICD-10-CM reference
G31: Other degenerative diseases of nervous system, not elsewhere classified
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Other degenerative diseases of nervous system, not elsewhere classified. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- G31.0: Frontotemporal dementiaNonbillable heading
- G31.1: Senile degeneration of brain, not elsewhere classifiedBillable code
- G31.2: Degeneration of nervous system due to alcoholBillable code
- G31.8: Other specified degenerative diseases of nervous systemNonbillable heading
- G31.9: Degenerative disease of nervous system, unspecifiedBillable code
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Excludes2
certain conditions originating in the perinatal period (P04-P96)
Source: G00-G99 (chapter, inherited).
Excludes2
certain infectious and parasitic diseases (A00-B99)
Source: G00-G99 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: G00-G99 (chapter, inherited).
Excludes2
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
Source: G00-G99 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: G00-G99 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: G00-G99 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: G00-G99 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: G00-G99 (chapter, inherited).
Instructional note
code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:
Source: G31 (category, direct).
Instructional note
dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
Source: G31 (category, direct).
Instructional note
dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
Source: G31 (category, direct).
Instructional note
dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
Source: G31 (category, direct).
Instructional note
dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
Source: G31 (category, direct).
Instructional note
dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
Source: G31 (category, direct).
Instructional note
mild neurocognitive disorder due to known physiological condition (F06.7-)
Source: G31 (category, direct).
Excludes2
Reye's syndrome (G93.7)
Source: G31 (category, direct).
Compare the FY2027 additions, removals and billable-status changes
What does G31 mean in FY2027?
The official ICD-10-CM descriptor is Other degenerative diseases of nervous system, not elsewhere classified. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is G31 billable in FY2027?
The FY2027 order file marks G31 as a nonbillable heading. Select a complete billable child code.
Does G31 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition