2026 ICD-10-CM Diagnosis Code F02.C18Dementia in other diseases classified elsewhere, severe, with other behavioral disturbance

ICD-10-CM Codes›F01–F99›F01-F09›F02

ICD-10-CM F02.C18
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F02.C18 is a billable ICD-10-CM diagnosis code for dementia in other diseases classified elsewhere, severe, with other behavioral disturbance. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurocognitive disorders.

Code Identity

ICD-10-CM Code
F02.C18
Billable Status
Yes — Valid for Submission
Code Describes
Dementia in other diseases classified elsewhere, severe, with other behavioral disturbance
Short Description
Dem in other dis classd elswhr, sev, with other beh distrb
Parent Code
F02.C1
Dementia in other diseases classified elsewhere, severe, with behavioral disturbance

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF01-F09Mental disorders due to known physiological conditions
CategoryF02Dementia in other diseases classified elsewhere
This CodeF02.C18Dementia in other diseases classified elsewhere, severe, with other behavioral disturbance

Code EditsBilling

Medicare Code Editor checks that affect claim validity for F02.C18.

Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Dementia in other diseases classified elsewhere, severe, with behavioral disturbances such as sleep disturbance, social disinhibition, or sexual disinhibition
  • Major neurocognitive disorder in other diseases classified elsewhere, severe, with behavioral disturbances such as sleep disturbance, social disinhibition, or sexual disinhibition

Use Additional Code

  • code, if applicable, to identify wandering in dementia in conditions classified elsewhere Z91.83

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Dementia(degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)
      • in (due to)
        • diseases specified elsewhere (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)
          • severe
            • with
              • behavioral disturbances (sexual disinhibition) (sleep disturbance) (social disinhibition)
    • Dementia(degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)
      • in (due to)
        • diseases specified elsewhere (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety)
          • severe
            • with
              • behavioral disturbances (sexual disinhibition) (sleep disturbance) (social disinhibition)
                • specified NEC

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS011
Neurocognitive disorders
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Dementia

Dementia is a loss of mental functions that is severe enough to affect your daily life and activities. These functions include:

The full article covers:

  • What is dementia?
  • What are the types of dementia?
  • Who is at risk for dementia?
  • What are the symptoms of dementia?
  • How is dementia diagnosed?
  • What are the treatments for dementia?
  • Can dementia be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code History & ChangesHistory

Replacement F02.C18 replaces the following previously assigned code(s):

  • F02.81 - Dem in other dis classd elswhr, unsp sev, with beh distrb
  • F02.81 - Dementia in oth diseases classd elswhr w behavioral disturb
FY 2023AddedAdded to the ICD-10-CM code setEffective October 1, 2022.
FY 2024–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About F02.C18Overview

Is F02.C18 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report dementia in other diseases classified elsewhere, severe, with other behavioral disturbance on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can F02.C18 be a principal diagnosis?

No. This is a manifestation code: dementia in other diseases classified elsewhere, severe, with other behavioral disturbance describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.