What is the ICD-10 code for Delirium due to known physiological condition?

The ICD-10-CM code for Delirium due to known physiological condition is F05 (fiscal year 2026). It is a billable diagnosis code.

What does ICD-10 code F05 mean?

F05 is the ICD-10-CM diagnosis code for Delirium due to known physiological condition. Delirium due to known physiological condition

Is F05 a billable ICD-10 code?

Yes, F05 is a billable ICD-10-CM code that can be used on medical claims.

What chapter is F05 in?

F05 is classified under Chapter 5: Mental, Behavioral and Neurodevelopmental disorders (F01-F99), Section F01-F09: Mental disorders due to known physiological conditions (F01-F09).

What are the includes and excludes for F05?

Excludes1 (not coded here): delirium NOS (R41.0). Excludes2 (not included here): delirium tremens alcohol-induced or unspecified (F10.231, F10.921).

F05 Delirium due to known physiological condition

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The ICD-10-CM code for Delirium due to known physiological condition is F05 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter: 5: Mental, Behavioral and Neurodevelopmental disorders (F01-F99)
Section: F01-F09: Mental disorders due to known physiological conditions (F01-F09)
Category F05: 1 code (1 billable)
FY2026 Status: Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to F05:

Sundowning
Twilight state › epileptic
Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure) › twilight
Psychosis, psychotic › infective (acute) (subacute)
Delirium, delirious (acute or subacute) (not alcohol- or drug-induced) › postprocedural (postoperative)
Confusion, confused › epileptic
Delirium, delirious (acute or subacute) (not alcohol- or drug-induced) › puerperal
Puerperal, puerperium (complicated by, complications) › delirium NEC

Excludes1

Not coded here. These conditions should NOT be coded together with F05.

delirium NOS (R41.0)

Excludes2

Not included here. These conditions are coded elsewhere but may be coded together if applicable.

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

Code First

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

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

U.S. Hospital Utilization

An estimated 381,900 U.S. inpatient stays in 2023 included F05 among the documented diagnoses.
1,710 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Pain disorders related to psychological factors (TOC entry)

a. Pain disorders related to psychological factors ..................................................................... 43

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.5.a

Psychoactive substance use disorders (TOC entry)

b. Mental and behavioral disorders due to psychoactive substance use ................................... 43

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.5.b

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026