F99
F99: Mental disorder, not otherwise specified
Billable / specific codeICD-10-CM
F99 is a billable, specific ICD-10-CM code for mental disorder, not otherwise specified. It is valid for submission on a claim.
Check F99 with the rest of the claim: free scrubberExcludes1: never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
- unspecified mental disorder due to known physiological condition (F09)
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Mental illness NOS
Other codes that can never be billed with F99
Their own Excludes1 notes name this code, so the conflict is not listed above.
Risk adjustment
No CMS-HCC V28 category: this code does not change a RAF score.
Medicare coverage
F99 is named in 5 Medicare coverage policies: 4 listing it as supporting medical necessity, and 1 listing it as NOT covered. Which one applies depends on your Medicare contractor.
- A52434Health and Behavior Assessment/Intervention – Medical Policy Articlenot covered
- A56756Billing and Coding: Home Health - Psychiatric Care
- A57480Billing and Coding: Psychiatry and Psychology Services
- A57520Billing and Coding: Psychiatric Diagnostic Evaluation and Psychotherapy Services
Alphabetic index entries that lead here
- Psychiatric disorder or problem
- Situation, psychiatric
- Aberration›mental
- Disease, diseased›mental
- Disease, diseased›psychiatric
- Disorder›mental(or behavioral) (nonpsychotic)
- Disorder›psychological
- Disturbance›mental
- Problem›psychiatric
- Reaction›psychogenic
Code history
Unchanged in every release from FY2024 to FY2027.