2027 ICD-10-CM Diagnosis Code F09Unspecified mental disorder due to known physiological condition
ICD-10-CM Codes›F01–F99›F01-F09›F09
- Billable — Valid for Submission
- Not Chronic
F09 is a billable ICD-10-CM diagnosis code for unspecified mental disorder due to known physiological condition. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 884, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Miscellaneous mental and behavioral disorders/conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Behavior disorder as sequela of cerebral infarction
- Chronic brain syndrome
- Chronic non-psychotic brain syndrome
- Chronic organic mental disorder
- Cognitive changes due to organic disorder
- Cognitive disorder
- Cognitive disorder in remission
- Encephalopathy with AIDS
- Neurocognitive disorder
- Neuropsychiatric disorder due to systemic lupus erythematosus
- Organic brain syndrome co-occurrent with human immunodeficiency virus infection
- Organic brain syndrome with AIDS
- Organic mental disorder
- Organic mental disorder caused by alcohol
- Organic mental disorder caused by hypnotic agent
- Organic mental disorder caused by sedative
- Specific nonpsychotic mental disorders following organic brain damage
- Transient organic mental disorder
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to F09: its own notes plus those printed at block F01-F09 and Chapter 5. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- disorders of psychological development
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- 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: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
- the underlying physiological condition
Notes
General instructions on how these codes are used.
- 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.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name F09, its category, or a range that includes it.
Applicable To 1
These notes mention F09.
- O99.34 Other mental disorders complicating pregnancy, childbirth, and the puerperium
Excludes1 2
These codes carry an Excludes1 note naming F09: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming F09: its condition is not part of those codes, and both may be reported when the patient has both.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
Disorder (of) See Also: Disease;
Organic See Also: condition;
brain syndrome F09
mental disorder F09
psychosis F09
organic F09
symptomatic F09
Syndrome See Also: Disease;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Mental Disorders
Mental disorders (or mental illnesses) are conditions that affect your thinking, feeling, mood, and behavior. They may happen over a short period of time or come and go. Some can be chronic (long-lasting). They can affect your ability to relate to others and function each day..
The full article covers:
- What are mental disorders?
- What are some types of mental disorders?
- What causes mental disorders?
- Who is at risk for mental disorders?
- How are mental disorders diagnosed?
- What are the treatments for mental disorders?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert F09 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About F09Overview
What is the ICD-10 code for unspecified mental disorder due to known physiological condition?
The ICD-10-CM code for unspecified mental disorder due to known physiological condition is F09. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is F09 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report unspecified mental disorder due to known physiological condition on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does F09 group to?
When unspecified mental disorder due to known physiological condition is the principal diagnosis on an inpatient stay, it groups to MS-DRG 884, 974, 976, 975, with relative weights from 0.7879 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.
Can F09 be reported with a code from F06.7?
Not as a rule. The Excludes1 note on F09 lists "mild neurocognitive disorder due to known physiological condition (F06.7-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is coded first with F09?
The Code First note reads: the underlying physiological condition. When one of these applies, it is sequenced before F09.
