F99 Mental disorder, not otherwise specified
Billable ICD-10-CM code, FY2026.
Applicable to
Excludes1 (never code together)
- unspecified mental disorder due to known physiological condition (F09)
Applies from F99 Mental disorder, not otherwise specified
Applicable to
Excludes1 (never code together)
- unspecified mental disorder due to known physiological condition (F09)
MS-DRG index
Defines the logic of DRG(s) 880 in MDC 19.
Approximate ICD-9-CM (GEMs)
300.9 Unspecified nonpsychotic mental disorder (approximate)
Code annotations containing back-references to F99
Back-references to F99
- Type 1 Excludes:
F29 Unspecified psychosis not due to a substance or known physiological condition ("mental disorder NOS (F99)") - Type 1 Excludes:
R46 Symptoms and signs involving appearance and behavior ("mental and behavioral disorders (F01-F99)")
Back-references to F99
- Type 1 Excludes:
F29 Unspecified psychosis not due to a substance or known physiological condition ("mental disorder NOS (F99)") - Type 1 Excludes:
R46 Symptoms and signs involving appearance and behavior ("mental and behavioral disorders (F01-F99)")
Diagnosis Index entries for F99
- Aberration › mental
- Disease, diseased › mental
- Disease, diseased › psychiatric
- Disorder (of) › mental (or behavioral) (nonpsychotic)
- Disorder (of) › psychological
- Disturbance (s) › mental
- Problem (with) (related to) › psychiatric
- Psychiatric disorder or problem
- Reaction › psychogenic
- Situation, psychiatric
Nearby codes
F99 Mental disorder, not otherwise specified (this code)