ICD-10-CM 2027
ICD-10 code for mild cognitive impairment
Confirmed by the official ICD-10-CM index entry “impaired, impairment (function) › cognitive, mild, of uncertain or unknown etiology”. Page updated September 29, 2026.
About coding mild cognitive impairment
The ICD-10-CM code for mild cognitive impairment is G31.84 (Mild cognitive impairment of uncertain or unknown etiology). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G31.84.
It is also searched as MCI.
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.
Related Mild cognitive impairment codes
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 impairment ICD-10 codes
What is the ICD-10 code for mild cognitive impairment?
- G31.84 — Mild cognitive impairment of uncertain or unknown etiology. More specific codes apply when the documentation supports them: F06.70, F06.71.
What is the ICD-10 code for mild neurocognitive disorder due to known physiological condition without behavioral disturbance?
- F06.70 — Mild neurocognitive disorder due to known physiological condition without behavioral disturbance.
What is the ICD-10 code for mild neurocognitive disorder due to known physiological condition with behavioral disturbance?
- F06.71 — Mild neurocognitive disorder due to known physiological condition with behavioral disturbance.
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.