2022 ICD-10-CM Diagnosis Code F99

Mental disorder, not otherwise specified

    2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
  • F99 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2022 edition of ICD-10-CM F99 became effective on October 1, 2021.
  • This is the American ICD-10-CM version of F99 - other international versions of ICD-10 F99 may differ.
Applicable To
  • Mental illness NOS
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 F99. 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.
  • unspecified mental disorder due to known physiological condition (
    ICD-10-CM Diagnosis Code F09

    Unspecified mental disorder due to known physiological condition

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    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
    • the underlying physiological condition
    Type 1 Excludes
    • psychosis NOS (F29)
    F09
    )
The following code(s) above F99 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to F99:
  • F01-F99
    2022 ICD-10-CM Range F01-F99

    Mental, Behavioral and Neurodevelopmental disorders

    Includes
    • disorders of psychological development
    Type 2 Excludes
    • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)
    Mental, Behavioral and Neurodevelopmental disorders
Approximate Synonyms
  • Emotional or mental disease in mother complicating
  • Mental disorder
  • Mental disorder in childbirth
  • Mental disorder in pregnancy
  • Mental disorder in the puerperium - baby delivered
  • Nonpsychotic psychological disorder after brain damage
  • Psychological disorder
  • Psychological disorder during pregnancy
  • Psychological disorder in pregnancy
  • Psychological illness, affecting pregnancy management after childbirth
  • Specific nonpsychotic mental disorders following organic brain damage
  • Unspecified psychological disorder
Clinical Information
  • A disorder characterized by behavioral and/or psychological abnormalities, often accompanied by physical symptoms. The symptoms may cause clinically significant distress or impairment in social and occupational areas of functioning. Representative examples include anxiety disorders, cognitive disorders, mood disorders and schizophrenia.
  • Any deviation from the normal structure or function of the brain and a psychiatric condition, that results in an impairment of an individual's normal cognitive, emotional, or behavioral functioning, and is caused by physiological or psychosocial factors.
  • Any of various conditions characterized by impairment of an individual's normal cognitive, emotional, or behavioral functioning, and caused by social, psychological, biochemical, genetic, or other factors, such as infection or head trauma; note behavior disorders are a subset of mental disorder.
  • Conceptually broad term referring to all forms of psychopathology. Use a more specific term if possible.
  • Mental disorders include a wide range of problems, including
    • anxiety disorders, including panic disorder, obsessive-compulsive disorder, post-traumatic stress disorder, and phobias
    • bipolar disorder
    • depression
    • mood disorders
    • personality disorders
    • psychotic disorders, including schizophrenia
    there are many causes of mental disorders. Your genes and family history may play a role. Your life experiences, such as stress or a history of abuse, may also matter. Biological factors can also be part of the cause. A traumatic brain injury can lead to a mental disorder. A mother's exposure to viruses or toxic chemicals while pregnant may play a part. Other factors may increase your risk, such as use of illegal drugs or having a serious medical condition like cancer.medications and counseling can help many mental disorders.
  • Psychiatric illness or diseases manifested by breakdowns in the adaptational process expressed primarily as abnormalities of thought, feeling, and behavior producing either distress or impairment of function.
ICD-10-CM F99 is grouped within Diagnostic Related Group(s) (MS-DRG v39.0):
  • 880 Acute adjustment reaction and psychosocial dysfunction

Convert F99 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
  • 2021 (effective 10/1/2020): No change
  • 2022 (effective 10/1/2021): No change
Code annotations containing back-references to F99:
  • Type 1 Excludes: F29
    ICD-10-CM Diagnosis Code F29

    Unspecified psychosis not due to a substance or known physiological condition

      2016 2017 2018 2019 2020 2021 2022 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)

Diagnosis Index entries containing back-references to F99:

ICD-10-CM Codes Adjacent To F99
F98.0 Enuresis not due to a substance or known physiological condition
F98.1 Encopresis not due to a substance or known physiological condition
F98.2 Other feeding disorders of infancy and childhood
F98.21 Rumination disorder of infancy
F98.29 Other feeding disorders of infancy and early childhood
F98.3 Pica of infancy and childhood
F98.4 Stereotyped movement disorders
F98.5 Adult onset fluency disorder
F98.8 Other specified behavioral and emotional disorders with onset usually occurring in childhood and adolescence
F98.9 Unspecified behavioral and emotional disorders with onset usually occurring in childhood and adolescence
F99 Mental disorder, not otherwise specified
G00 Bacterial meningitis, not elsewhere classified
G00.0 Hemophilus meningitis
G00.1 Pneumococcal meningitis
G00.2 Streptococcal meningitis
G00.3 Staphylococcal meningitis
G00.8 Other bacterial meningitis
G00.9 Bacterial meningitis, unspecified
G01 Meningitis in bacterial diseases classified elsewhere
G02 Meningitis in other infectious and parasitic diseases classified elsewhere
G03 Meningitis due to other and unspecified causes

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.