2025 ICD-10-CM code F09
Unspecified mental disorder due to a known physiological condition. This code is used when the provider does not specify the type of mental disorder but documents a physiological cause, which should be coded first.
Medical necessity is established by the documented presence of a mental disorder caused by a known physiological condition. The documentation must link the mental disorder to the underlying physiological problem and justify the need for treatment and/or further diagnostic evaluation.
Diagnosis involves patient history, signs and symptoms, physical and neuropsychological examination. Interviews with family or caregivers may help clarify symptoms. Laboratory studies, CT, MRI of the brain, and EEG may be used. Treatment depends on the underlying cause and may include medications like antidepressants or antipsychotics, and supportive care.
- Chapter V: Mental and behavioural disorders
- F01-F09: Organic, including symptomatic, mental disorders
In simple words: This code describes a mental health problem caused by a physical issue in the brain. The doctor knows the physical cause, but hasn't identified the specific type of mental problem.
Unspecified mental disorder due to known physiological condition refers to a mental disorder caused by brain damage or dysfunction due to a previously diagnosed disease or condition.The specific type of mental disorder is not specified by the provider. It is essential to document and code the underlying physiological condition first.
Example 1: A patient with a history of traumatic brain injury exhibits various cognitive and behavioral changes, but no specific mental disorder is diagnosed. The underlying TBI is coded first, followed by F09., A patient with a long-standing diagnosis of multiple sclerosis develops unspecified cognitive impairment. MS is coded first, then F09 for the unspecified mental disorder., A patient with a history of stroke presents with altered mental status and behavioral changes, but the specific mental disorder remains undiagnosed. The stroke is coded, followed by F09.
Documentation should clearly state the known physiological condition causing the mental disorder. Details of the patient's mental state, including cognitive and behavioral changes, should be recorded. Results of any diagnostic tests, such as blood tests, CT, MRI, or EEG, should be included.
** Excludes1: mild neurocognitive disorder due to known physiological condition (F06.7-), psychosis NOS (F29). Excludes2: symptoms, signs, and abnormal clinical laboratory findings, not elsewhere classified (R00-R99).
- Payment Status: Active
- Specialties:Neurology, Psychiatry, Internal Medicine, Family Medicine
- Place of Service:Inpatient Hospital, Outpatient Hospital, Office, Skilled Nursing Facility, Nursing Facility