2027 ICD-10-CM Diagnosis Code F03.C4Unspecified dementia, severe, with anxiety

ICD-10-CM Codes›F01–F99›F01-F09›F03

ICD-10-CM F03.C4
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

F03.C4 is a billable ICD-10-CM diagnosis code for unspecified dementia, severe, with anxiety. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 884. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 20 closely related codes. 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.

For Medicare Advantage risk adjustment, F03.C4 maps to CMS-HCC Category 125 (Dementia, Severe) under the V28 model, adding a risk factor of about 0.341 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
F03.C4
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified dementia, severe, with anxiety
Short Description
Unspecified dementia, severe, with anxiety
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.C4Unspecified dementia, severe, with anxiety

Code EditsBilling

Medicare Code Editor checks that affect claim validity for F03.C4.

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).

Medicare Risk Adjustment (HCC)Billing

F03.C4 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 125— Dementia, Severe
Payment HCC · PY 2027 one of 18 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.341
community, non-dual, aged · ranges 0.000–0.438 across segments
Hierarchy
Supersedes HCC 126 and HCC 127
less severe related categories are not paid alongside HCC 125
Prior Model (CMS-HCC V24)
HCC 51
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
ESRD (V21): HCC 51 · ESRD (V24): HCC 51
ESRD V21 weights: 0.097 dialysis, 0.000–0.643 functioning graft · ESRD V24 weights: 0.042 dialysis, 0.000–0.399 functioning graft
Part D (RxHCC)
RxHCC 112 — Dementia, Except Alzheimer's Disease
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to F03.C4: its own notes plus those printed at F03, block F01-F09, and Chapter 5. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • disorders of psychological development

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From F03 Unspecified dementia applies to 24 codes
  • dementia with delirium or acute confusional state (F05)
  • mild memory disturbance due to known physiological condition (F06.8)
From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)

Notes

General instructions on how these codes are used.

From Block F01-F09 Mental disorders due to known physiological conditions applies to 91 codes
  • This block comprises a range of mental disorders grouped together on the basis of their having in common a demonstrable etiology in cerebral disease, brain injury, or other insult leading to cerebral dysfunction. The dysfunction may be primary, as in diseases, injuries, and insults that affect the brain directly and selectively; or secondary, as in systemic diseases and disorders that attack the brain only as one of the multiple organs or systems of the body that are involved.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name F03.C4, its category, or a range that includes it.

Applicable To 1

These notes mention F03.C4.

  • O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperium
    Conditions in F01-F09, F20-F52 and F54-F99 names F01-F09, which includes this code

Excludes1 5

These codes carry an Excludes1 note naming F03.C4: they are not reported together with it, unless the two conditions are unrelated.

  • F06 Other mental disorders due to known physiological condition
    unspecified dementia (F03.-) names F03.-, which includes this code
  • F06.7 Mild neurocognitive disorder due to known physiological condition
    dementia (F01.-, F02.-, F03.-) names F03.-, which includes this code
  • G30 Alzheimer's disease
    senile dementia NOS (F03.-) names F03.-, which includes this code
  • G31.84 Mild cognitive impairment of uncertain or unknown etiology
    dementia (F01.-, F02.-, F03.-) names F03.-, which includes this code
  • R54 Age-related physical debility
    senile psychosis (F03.-) names F03.-, which includes this code

Excludes2 2

These codes carry an Excludes2 note naming F03.C4: its condition is not part of those codes, and both may be reported when the patient has both.

  • F63.1 Pyromania
    mental disorders due to known physiological condition (F01-F09) names F01-F09, which includes this code
  • F63.2 Kleptomania
    stealing in mental disorders due to known physiological condition (F01-F09) names F01-F09, which includes this code

Code First 1

These codes say to code first a condition named in the note, and F03.C4 is one of the conditions named.

  • Z91.83 Wandering in diseases classified elsewhere
    unspecified dementia with behavioral disturbance (F03.9-, F03.A-, F03.B-, F03.C-) names F03.C-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

Anxiety

Anxiety is a feeling of fear, dread, and uneasiness. It might cause you to sweat, feel restless and tense, and have a rapid heartbeat. It can be a normal reaction to stress. For example, you might feel anxious when faced with a difficult problem at work, before taking a test, or before making an important decision.

The full article covers:

  • What is anxiety?
  • What are anxiety disorders?
  • What are the types of anxiety disorders?
  • What causes anxiety disorders?
  • Who is at risk for anxiety disorders?
  • What are the symptoms of anxiety disorders?
  • How are anxiety disorders diagnosed?
  • What are the treatments for anxiety disorders?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement F03.C4 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 2024–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About F03.C4Overview

What is the ICD-10 code for unspecified dementia, severe, with anxiety?

The ICD-10-CM code for unspecified dementia, severe, with anxiety is F03.C4 (sometimes written as F03C4). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is F03.C4 (Unspecified dementia, severe) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified dementia, severe, with anxiety on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does F03.C4 group to?

When unspecified dementia, severe, with anxiety is the principal diagnosis on an inpatient stay, it groups to MS-DRG 884 (organic Disturbances and Intellectual Disability), which carries a relative weight of 1.5998. Higher weights mean higher Medicare reimbursement.

Is F03.C4 a CC or MCC?

CMS lists F03.C4 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 20 closely related codes in its exclusion list.

Who can F03.C4 be reported for?

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

What HCC is F03.C4?

F03.C4 (unspecified dementia, severe, with anxiety) maps to CMS-HCC Category 125 (Dementia, Severe), commonly written as HCC 125, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 51 under the retired V24 model. It also maps in the ESRD (V21) and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 112.

Does F03.C4 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, F03.C4 adds a risk adjustment factor of about 0.341 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.000 to 0.438 depending on the payment segment). HCC 125 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 125 category page.