F99 is a billable/specific diagnosis code from the 2025 ICD-10-CM used to classify the following condition: Mental disorder, not otherwise specified.
Inclusion term
Mental illness NOS
Type 1 excludes
Unspecified mental disorder due to known physiological condition (F09)
Versions
2025
No changes
2024
No changes
2023
No changes
2022
No changes
2021
No changes
2020
No changes
2019
No changes
2018
No changes
2017
No changes
2016
New code