Unspecified mental disorder due to known physiological condition 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
Code First
Code First Help
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, 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. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • the underlying physiological condition
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as F09. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • psychosis NOS (
    ICD-10-CM Diagnosis Code F29

    Unspecified psychosis not due to a substance or known physiological condition

      2016 2017 2018 2019 2020 2021 Billable/Specific Code
    Applicable To
    • Psychosis NOS
    • Unspecified schizophrenia spectrum and other psychotic disorder
    Type 1 Excludes
    • mental disorder NOS (F99)
    • unspecified mental disorder due to known physiological condition (F09)
Clinical Information
  • Broad group of severe mental and behavioral disorders etiologically traceable to brain disease, injury, or toxicosis; psychosis associated with endocrine disorders, drugs, and metabolic or nutritional abnormalities.
  • Cognitive disorders including delirium, dementia, and other cognitive disorders. These may be the result of substance use, trauma, or other causes.
  • What: organic brain syndrome. Organic brain syndrome: either a long term deterioration of intellectual function and memory (dementia) or a short term disturbance of orientation, judgement, or consciousness (delirium). Both may be marked by illusions, hallucinations, delusions, or disturbances of perceptions, mood, behavior, cognitive capacity, or personality. Why: delirium can occur with rheumatic fever or cerebral vasculitis. Both delirium and dementia can occur in systemic lupus erythematosus, and rarely also in mixed connective tissue disease. How: ten or more incorrect responses to the following 30 questions usually means an organic impairment exists. 1) what day of the week is this? 15) the opposite of fast is slow. 2) what month? the opposite of up is? 3) what day of the month? 16) the opposite of large is? 4) what year? 17) the opposite of hard is? 5) what place is this? 18) an orange and a banana are 6) repeat these numbers 8 7 2. Both fruits. A penny and a 7) say them backwards. Dime are both? 8) repeat these numbers 6 3 7 1. 19) red and blue are both? 9) listen to these numbers 6 9 4. 20) what are those words i asked count 1 through 10 out loud, you to remember? (hat) then repeat 6 9 4. (help if 21) (car) needed; then use 5 7 3.) 22) (tree) 10) listen to these numbers 8 1 23) (twenty-six) 4 3. Count 1 through 10 out 24) 100 minus 7 is? loud; then repeat 8 1 4 3. 25) minus 7 is? 11) beginning with sunday, say the 26) minus 7 is? days of the week backwards. 27) minus 7 is? 12) 9 + 3 is? 28) minus 7 is? 13) add 6 (to answer of 12). 29) minus 7 is? 14) take away 5 (from answer of 18). 30) minus 7 is? repeat these words after me and remember them. I will ask for them later. Hat, car, tree, twenty-six. Refs: 1) "organic brain syndromes". In diagnostic and statistical manual of mental disorders, 3rd ed. (dsm iii). Washington, d.c.: american psychiatric association, 1980. 2) west, nd: "organic brain syndromes". In psychiatry in primary care medicine (ch. 2). Chicago: year book medical publishers, inc., 1979. 3) sharp, gc: "mixed connective tissue disease and overlap syndromes". In textbook of rheumatology (ch. 71). Philadelphia: w.b. Saunders co., 1981. 4) bennet, rm and spargo, bh: neuropsychiatric problems in mixed connective tissue disease. Am j med 65(6), december 1978, pp. 955-62. Dn193071. 5) jacobs, et al.: screening for organic mental syndromes in the medically ill. Ann intern med 86(1), january 1977, pp. 40-46. Dn19308-9.
  • F09 Unspecified mental disorder due to known physiological condition