F99
Mental disorder, not otherwise specified
Billable code
This code does not map to a risk-adjusting HCC in the loaded models.
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
This code · F99
Excludes 1
unspecified mental disorder due to known physiological condition (F09)
Synonyms
Mental illness NOS
Inherited from chapter 5Mental, Behavioral and Neurodevelopmental disorders
Includes
disorders of psychological development
Excludes 2
symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)
Official Guidelines for F99
FY 2026 ›Find F99 in the alphabetic index
10 index paths lead to this code