Is F05 a billable ICD-10-CM code?

Yes. F05 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does F05 sit in the tabular list?

Mental, Behavioral and Neurodevelopmental disorders (F01-F99), in the block Mental disorders due to known physiological conditions (F01-F09).

What cannot be coded together with F05?

F05 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

F05

F05 — Delirium due to known physiological condition

Billable / specific codeICD-10-CM

F05 is a billable, specific ICD-10-CM code for delirium due to known physiological condition. It is valid for submission on a claim.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

delirium NOS (R41.0)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

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

Code first

The underlying condition must be sequenced before this code.

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

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

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

Other codes that can never be billed with F05

These codes carry an Excludes1 note pointing at F05. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading F05 alone.

R41.0Disorientation, unspecified

Risk adjustment

F05 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

F05 is named in 21 Medicare coverage policies — 20 listing it as supporting medical necessity, and 1 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A52434Health and Behavior Assessment/Intervention – Medical Policy Articlenot covered
A53134Billing and Coding: NCD Coding Article for Positron Emission Tomography (PET) Scans Used for Non-Oncologic Conditions
A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
A56612Billing and Coding: CT of the Head

How F05 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to F05.

Sundowning
Confusion, confused›epileptic
Delirium, delirious›postprocedural(postoperative)
Delirium, delirious›puerperal
Epilepsy, epileptic, epilepsia›twilight
Psychosis, psychotic›infective(acute) (subacute)
Puerperal, puerperium›delirium NEC
Twilight state›epileptic
Delirium, delirious›due to›general medical condition
Delirium, delirious›due to›multiple etiologies
Delirium, delirious›with›dementia
Dementia›with›acute confusional state

Questions about F05

Is F05 a billable ICD-10-CM code?: Yes. F05 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does F05 sit in the tabular list?: Mental, Behavioral and Neurodevelopmental disorders (F01-F99), in the block Mental disorders due to known physiological conditions (F01-F09).
What cannot be coded together with F05?: F05 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.