Mental disorder, not otherwise specified
Billable / specific
F99 is a billable, specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes in FY2027.
Inclusion terms
Includes
- disorders of psychological development
Applicable to
- Mental illness NOS
Excludes1
Not coded here — never report together with this code.
- unspecified mental disorder due to known physiological condition (F09)
Excludes2
Not included here — may be reported together when both conditions exist.
Also known as
- Mental illness NOS
- Aberration, mental
- Disease, diseased, mental
- Disease, diseased, psychiatric
- Disorder, mental
- Disorder, psychological
- Disturbance, mental
- Problem, psychiatric
- Psychiatric disorder or problem
- Reaction, psychogenic
- Situation, psychiatric