F05 Delirium due to known physiological condition

Billable

Block: Mental disorders due to known physiological conditions (F01-F09)

Includes

  • 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

Excludes 1 (cannot be coded together)

  • delirium NOS (R41.0)

Excludes 2 (not included here)

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

Code First

  • the underlying physiological condition, such as:
  • dementia (F03.9-)
This category is a complete, billable diagnosis code.

No additional specificity is required — submit F05 directly on claims and documentation without a subcode extension.

Last reviewed: September 2026