F05

Delirium due to known physiological condition

Billable FY2026 2025-10-01 → 2026-09-30

Exclusions 3 never code together

F05code

Excludes1

delirium NOS (R41.0)R41.0 R41.0 R41.0

Excludes2

delirium tremens alcohol-induced or unspecified (F10.231, F10.921)F10.231 F10.231 F10.231 F10.921 F10.921 F10.921

F01-F99chapter

Excludes2

symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)R00-R99

Excludes1 — never code together. The excluded condition and this one are mutually exclusive.

Excludes2 — not included here, but the patient may have both. Code both when documented.

Instructional notes 12

F05code

Inclusion terms

Acute or subacute brain syndrome
Acute or subacute confusional state (nonalcoholic)
Acute or subacute infective psychosis
Acute or subacute organic reaction
Acute or subacute psycho-organic syndrome
Delirium of mixed etiology
Delirium superimposed on dementia
Sundowning

Code first

the underlying physiological condition, such as:
dementia (F03.9-)F03.9-F03.9-F03.9-

F01-F09block

Notes

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.

F01-F99chapter

Includes

disorders of psychological development

Index entries leading here 12

State (of)
- confusional (psychogenic) F44.89
  - acute — see also Delirium
    - with
      - senility or dementia F05
  - epileptic F05
- twilight
  - epileptic F05
Senile, senility R41.81
- with
  - acute confusional state F05
Dementia (degenerative (primary)) (persisting) (unspecified severity) (without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety) F03.90
- with
  - acute confusional state F05
Psychosis, psychotic F29
- organic F09
  - due to or associated with
    - infection
      - brain (intracranial) F06.8
        
        acute or subacute F05
    - trauma, brain (birth) (from electric current) (surgical) F06.8
      - acute or subacute F05
    - disease
      - endocrine or metabolic F06.8
        
        acute or subacute F05
    - epilepsy transient (acute) F05
  - infective F06.8
    - acute or subacute F05
  - post-traumatic F06.8
    - acute or subacute F05
- confusional F29
  - acute or subacute F05
- infective (acute) (subacute) F05
Syndrome — see also Disease
- psycho-organic (nonpsychotic severity) F07.9
  - acute or subacute F05
Insanity, insane — see also Psychosis
- confusional F28
  - acute or subacute F05
Confusion, confused R41.0
- epileptic F05
Delirium, delirious (acute or subacute) (not alcohol- or drug-induced) R41.0
- due to (secondary to)
  - general medical condition F05
  - multiple etiologies F05
- postprocedural (postoperative) F05
- puerperal F05
- with
  - dementia F05
Puerperal, puerperium (complicated by, complications)
- delirium NEC F05
Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure) G40.909
- twilight F05
Twilight state
- epileptic F05
Sundowning F05

Additional references

AHA Coding Clinic® Licence required

Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.

Risk adjustment

Maps to no condition category in any loaded model.

Presence is a property of the code. Untick a model to hide it everywhere.

This code

Billable: yes
Code set: FY2026
Block: F01-F09

Present FY2024–FY2027.