F99Billable
Mental disorder, not otherwise specified
- Chapter
- 5. Mental, Behavioral and Neurodevelopmental disorders
- Category
- F99
- Effective date
- October 1, 2026
Frequently asked questions
What is ICD-10 code F99?
F99 is an ICD-10-CM diagnosis code for Mental disorder, not otherwise specified.
Is F99 a billable code?
Yes. F99 is billable and specific enough to be used on a claim.
What ICD-10-CM chapter is F99 in?
F99 falls under Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.
When did F99 become effective?
F99 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.