F03.A18 Unspecified dementia, mild, with other behavioral disturbance

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Unspecified dementia, mild, with behavioral disturbances such as sleep disturbance, social disinhibition, or sexual disinhibition

Use additional code

• code, if applicable, to identify wandering in unspecified dementia (Z91.83)

Applies from F03 Unspecified dementia

Applicable to

• Major neurocognitive disorder NOS
• Presenile dementia NOS
• Presenile psychosis NOS
• Primary degenerative dementia NOS
• Senile dementia NOS
• Senile dementia depressed or paranoid type
• Senile psychosis NOS

Excludes2 (not included here)

• dementia with delirium or acute confusional state (F05)
• mild memory disturbance due to known physiological condition (F06.8)

Applies from F03.A Unspecified dementia, mild

Excludes1 (never code together)

• mild neurocognitive disorder due to known physiological condition with or without behavioral disturbance (F06.7-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 127 — Dementia, Mild or Unspecified
• RxHCC V08: HCC 112 — Dementia, Except Alzheimer's Disease
• ESRD V24: HCC 51

MS-DRG index

Defines the logic of DRG(s) 884 in MDC 19.

Medicare Code Edits (MCE v43.1 (April 2026))

• Adult diagnoses (age 15 through 124): Age conflict edit. These diagnoses are clinically expected only in patients age 15 through 124.

Code annotations containing back-references to F03.A18

Back-references to F03.A

• Code First: Z91.83 Wandering in diseases classified elsewhere ("unspecified dementia with behavioral disturbance (F03.9-, F03.A-, F03.B-, F03.C-)")

Back-references to F03

• Type 1 Excludes: F06 Other mental disorders due to known physiological condition ("unspecified dementia (F03.-)")
• Type 1 Excludes: F06.7 Mild neurocognitive disorder due to known physiological condition ("dementia (F01.-, F02.-, F03.-)")
• Type 2 Excludes: F63.1 Pyromania ("mental disorders due to known physiological condition (F01-F09)")
• Type 2 Excludes: F63.2 Kleptomania ("stealing in mental disorders due to known physiological condition (F01-F09)")
• Type 1 Excludes: G30 Alzheimer's disease ("senile dementia NOS (F03.-)")
• Type 1 Excludes: G31.84 Mild cognitive impairment of uncertain or unknown etiology ("dementia (F01.-, F02.-, F03.-)")
• Type 1 Excludes: R54 Age-related physical debility ("senile psychosis (F03.-)")

Diagnosis Index entries for F03.A18

• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › mild › with › behavioral disturbances (sexual disinhibition) (sleep disturbance) (social disinhibition)
• Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) › mild › with › behavioral disturbances (sexual disinhibition) (sleep disturbance) (social disinhibition) › specified NEC

Nearby codes

• F03.94 Unspecified dementia, unspecified severity, with anxiety
• F03.A Unspecified dementia, mild
• F03.A0 Unspecified dementia, mild, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety
• F03.A1 Unspecified dementia, mild, with behavioral disturbance
• F03.A11 Unspecified dementia, mild, with agitation
• F03.A18 Unspecified dementia, mild, with other behavioral disturbance (this code)
• F03.A2 Unspecified dementia, mild, with psychotic disturbance
• F03.A3 Unspecified dementia, mild, with mood disturbance
• F03.A4 Unspecified dementia, mild, with anxiety
• F03.B Unspecified dementia, moderate
• F03.B0 Unspecified dementia, moderate, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety