2026 ICD-10-CM Diagnosis Code F03.C3Unspecified dementia, severe, with mood disturbance

ICD-10-CM Codes›F01–F99›F01-F09›F03

ICD-10-CM F03.C3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F03.C3 is a billable ICD-10-CM diagnosis code for unspecified dementia, severe, with mood disturbance. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is restricted by the Medicare Code Editor to adult patients (age 15 through 124). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neurocognitive disorders.

Code Identity

ICD-10-CM Code
F03.C3
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified dementia, severe, with mood disturbance
Short Description
Unspecified dementia, severe, with mood disturbance
Same as the full description in the CMS dataset.
Parent Code
F03.C
Unspecified dementia, severe

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF01-F09Mental disorders due to known physiological conditions
CategoryF03Unspecified dementia
This CodeF03.C3Unspecified dementia, severe, with mood disturbance

Code EditsBilling

Medicare Code Editor checks that affect claim validity for F03.C3.

Adult diagnoses
The Medicare Code Editor detects inconsistencies in adult cases by checking a patient's age and any diagnosis on the patient's record. The adult code edits apply to patients age range is 15–124 years inclusive (e.g., senile delirium, mature cataract).

Tabular List NotesGuidance

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

Inclusion Terms

  • Unspecified dementia, severe, with mood disturbance such as depression, apathy, or anhedonia

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)
      • severe
        • with
          • mood disturbance (anhedonia) (apathy) (depression)

Clinical ClassificationClinical

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

CCSR NVS011
Neurocognitive disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

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 F03.C3 replaces the following previously assigned code(s):

  • F03.91 - Unsp dementia, unspecified severity, with behavioral disturb
  • F03.91 - Unspecified dementia with behavioral disturbance
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 F03.C3Overview

Is F03.C3 (Unspecified dementia, severe) a billable code?

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

Who can F03.C3 be reported for?

The Medicare Code Editor checks unspecified dementia, severe, with mood disturbance against patient demographics: this code is intended for adult patients (age 15 through 124). Claims outside these limits are flagged as inconsistent.

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.