F09 – Unspecified mental disorder due to known physiological condition
ICD-10-CM 2027 diagnosis code · Mental disorders due to known physiological conditions
ICD-10-CM code
F09
- Code
F09(claims format:F09)- Description
- Unspecified mental disorder due to known physiological condition
- Short description
- Unsp mental disorder due to known physiological condition
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 5. Mental, Behavioral and Neurodevelopmental disorders (F01-F99)
- Block
- F01-F09 Mental disorders due to known physiological conditions
Notes for F09
Applicable to:
- Mental disorder NOS due to known physiological condition
- Organic brain syndrome NOS
- Organic mental disorder NOS
- Organic psychosis NOS
- Symptomatic psychosis NOS
Excludes1 (not coded here):
Code first:
- the underlying physiological condition
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
Block F01-F09
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.
Index terms for F09
Entries in the ICD-10-CM alphabetic index that lead to this code:
- Syndrome, brain
- Organic, psychosis
- Disorder, cognitive
- Organic, brain syndrome
- Syndrome, organic, brain
- Syndrome, brain, organic
- Organic, mental disorder
- Disorder, cognitive, due to
- Psychosis, psychotic, organic
- Syndrome, brain, psycho-organic
- Deficiency, deficient, cognitive
- Psychosis, psychotic, symptomatic
- Disease, diseased, mental, organic
- Disorder, mental, organic or symptomatic
- Disorder, mental, due to, general medical condition
- Syndrome, brain, with psychosis, psychotic reaction
- Syndrome, brain, organic, post-traumatic, psychotic
- Disorder, mental, due to, brain disease, damage and dysfunction
Frequently asked questions
What is ICD-10 code F09?
F09 is the ICD-10-CM code for unspecified mental disorder due to known physiological condition, in the block F01-F09 (Mental disorders due to known physiological conditions).
Is F09 a billable code?
Yes. F09 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.