ICD-10-CM 2027 diagnosis code
F03.C18Unspecified dementia, severe, with other behavioral disturbance
F03.C18 is a valid, billable ICD-10-CM code for unspecified dementia, severe, with other behavioral disturbance. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Unspecified dementia, severe, with other behavioral disturb
Code last changed in FY2023 (effective October 1, 2022). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About F03.C18
F03.C18 is the ICD-10-CM diagnosis code for unspecified dementia, severe, with other behavioral disturbance. It belongs to category F03 (unspecified dementia), block F01-F09 (mental disorders due to known physiological conditions) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within F03.C1, choose F03.C18 (other behavioral disturbance) only when documentation doesn't support a more specific option: agitation (F03.C11).
Use an additional code, if applicable, to identify wandering in unspecified dementia (Z91.83).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 884 (Organic Disturbances and Intellectual Disability, relative weight 1.6001), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
The Medicare Code Editor expects this diagnosis only for patients age 15 through 124.
It was added in FY2023, effective October 1, 2022.
Coding notes
- Unspecified dementia, severe, with behavioral disturbances such as sleep disturbance, social disinhibition, or sexual disinhibition
- code, if applicable, to identify wandering in unspecified dementia (Z91.83)
Notes that apply from higher levels
Instructions written at a parent level also apply to F03.C18.
› From F03 Unspecified dementia
Broader instructions also apply from F01-F09 Mental disorders due to known physiological conditions and Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.
Alphabetic index entries
2 entriesTerms in the official ICD-10-CM index that lead to F03.C18.
- Dementia (degenerative (primary)) (persisting) (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) › severe › with › behavioral disturbances (sexual disinhibition) (sleep disturbance) (social disinhibition) › specified NEC
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 19 · Mental Diseases and Disorders
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2023 (effective 10/1/2022): Added
- No changes since FY2023.
Common questions about F03.C18
Is F03.C18 billable?
- Yes. F03.C18 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can F03.C18 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict F03.C18 as a principal diagnosis.
Is F03.C18 a CC or MCC?
- F03.C18 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does F03.C18 group to?
- F03.C18 is used in the MS-DRG v44.0 logic for MS-DRG 884 (Organic Disturbances and Intellectual Disability). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.