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  2. ICD-10-CM Codes List
  3. F01–F99
  4. F01-F09
  5. Unspecified mental disorder due to known physiological condition (F09)

Unspecified mental disorder due to known physiological condition (F09)

The ICD-10 code F09 is used to classify unspecified mental disorders that arise from a known physiological condition. It captures cases where a medical cause for the mental disorder is recognized, but the specific mental health features are not distinctly classified.

This code covers a broad range of conditions often referred to by synonyms such as organic mental disorder, neurocognitive disorder, or chronic organic mental disorder. It includes mental changes linked with systemic illnesses like lupus or HIV/AIDS, and cognitive or behavioral disorders triggered by substances such as ethanol, sedatives, or hypnotic agents. Conditions like transient organic mental disorders or cognitive and behavior disorders following brain injury also fall under this code. Using ICD-10 code F09 helps healthcare professionals accurately record mental disorders influenced significantly by physical causes, even when the precise mental symptoms are not otherwise specified, ensuring clarity when coding complex organic brain syndromes and associated cognitive impairments.

Instructional Notations

Inclusion Terms

These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.

  • Mental disorder NOS due to known physiological condition
  • Organic brain syndrome NOS
  • Organic mental disorder NOS
  • Organic psychosis NOS
  • Symptomatic psychosis NOS

Code First

Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.

  • the underlying physiological condition

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • mild neurocognitive disorder due to known physiological condition F06.7
  • psychosis NOS F29