ICD-10 G31.84
Billable / SpecificMild cognitive impairment of uncertain or unknown etiology
About ICD-10-CM G31.84
ICD-10-CM code G31.84 represents Mild cognitive impairment of uncertain or unknown etiology. This is a billable/specific code in the Nervous System chapter (block G31). The 2026 edition of ICD-10-CM G31.84 became effective on October 1, 2025.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under G31.84. Per CMS ICD-10-CM Tabular 2026.
- Mild cognitive disorder NOS
- Mild neurocognitive disorder of uncertain or unknown etiology
Type 1 Excludes
Pure excludes, these codes can never be coded together with G31.84. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- 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)
Use Additional Code
When coding G31.84, also report these additional codes when applicable.
- 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)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Medicare LCD Coverage for G31.84
Local Coverage Determinations (LCDs) from CMS MACs that list G31.84 as a covered diagnosis.
Showing top 10 of 172 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing G31.84.
2 Aetna
3 Cigna
5 Medicare
CPT Codes Commonly Billed with G31.84
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Convert G31.84 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| G31.84 | 33183 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To G31.84
Other codes in section G30-G32 (Other degenerative diseases of the nervous system).
ICD-10 G31.84, Billing FAQ
Is ICD-10 code G31.84 billable? +
Yes, G31.84 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to G31.84? +
ICD-10 G31.84 includes: Mild cognitive disorder NOS; Mild neurocognitive disorder of uncertain or unknown etiology.
What codes are Type 1 Excludes for G31.84? +
Type 1 Excludes (never code together with G31.84): age related cognitive decline (R41.81); altered mental status (R41.82); cerebral degeneration (G31.9)
What ICD-9 codes does G31.84 map to? +
Per CMS GEMs, G31.84 maps to ICD-9 codes: 33183. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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