ICD-10-CM 2027
ICD-10 code for mild cognitive impaired
From the official ICD-10-CM alphabetic index entry “Impaired, impairment (function) › mild cognitive”. Page updated September 29, 2026.
About coding mild cognitive impaired
The ICD-10-CM code for mild cognitive impaired is G31.84 (Mild cognitive impairment of uncertain or unknown etiology). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on G31.84.
Within G31.8 (other specified degenerative diseases of nervous system), G31.84 is specifically for mild cognitive impairment of uncertain or unknown etiology. Related codes cover leukodystrophy, unspecified (G31.80), Alpers disease (G31.81), Leigh's disease (G31.82), neurocognitive disorder with Lewy bodies (G31.83), Corticobasal degeneration (G31.85), Alexander disease (G31.86), primary progressive apraxia of speech (G31.87) and other specified degenerative diseases of nervous system (G31.89).
Don't report G31.84 together with the conditions in its Excludes1 note: age related cognitive decline (R41.81), altered mental status (R41.82), cerebral degeneration (G31.9), cerebrovascular diseases (I60-I69) and 7 more.
Use an additional code to identify presence of: alcohol abuse and dependence (F10.-), exposure to environmental tobacco smoke (Z77.22), history of tobacco dependence (Z87.891), hypertension (I10-I1A), occupational exposure to environmental tobacco smoke (Z57.31) and 2 more. Use an additional 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.
More specific mild cognitive impaired codes (official index)
- of uncertain or unknown etiology G31.84 — Mild cognitive impairment of uncertain or unknown etiology
Don't confuse with (Excludes1 for G31.84)
- age related cognitive decline (R41.81)
- altered mental status (R41.82)
- cerebral degeneration (G31.9)
- cerebrovascular diseases (I60-I69)
- change in mental status (R41.82)
- cognitive deficits following (sequelae of) cerebral hemorrhage or infarction (I69.01-, I69.11-, I69.21-, I69.31-, I69.81-, I69.91-)
- cognitive impairment due to intracranial or head injury (S06.-)
- dementia (F01.-, F02.-, F03.-)
- mild neurocognitive disorder due to a known physiological condition (F06.7-)
- neurologic neglect syndrome (R41.4)
- personality change, nonpsychotic (F68.8)
Common questions about mild cognitive impaired ICD-10 codes
What is the ICD-10 code for mild cognitive impaired?
- G31.84 — Mild cognitive impairment of uncertain or unknown etiology. More specific codes apply when the documentation supports them: G31.84.
Is G31.84 billable?
- Yes. G31.84 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G31.84 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G31.84 as a principal diagnosis.
Is G31.84 a CC or MCC?
- No. G31.84 is neither a CC nor an MCC under MS-DRG v44.0.