ICD-10-CM
ICD-10 code for Disease, diseased psychiatric: F99
The ICD-10-CM index points "Disease, diseased psychiatric" to F99, Mental disorder, not otherwise specified. F99 is a billable code.
Source: CDC ICD-10-CM FY2027 Alphabetic Index file dated June 16, 2026. Publisher page
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Excludes1
Excludes1 means these codes are not reported together.
Related conditions
Related pages
- F99 code detailsNotes, nearby codes, CMS-HCC group
- Chapter 5Mental, behavioral and neurodevelopmental disorders
- ICD-10 codes by conditionA to Z
- Check a list of ICD-10 codes
- Denial code CO-11Diagnosis does not support the procedure
- Denial code CO-146Diagnosis invalid for the date of service
- HCPCS Level II code lookup
Questions
What is the ICD-10 code for Disease, diseased psychiatric?
The ICD-10-CM index points "Disease, diseased psychiatric" to F99, Mental disorder, not otherwise specified. F99 is a billable code.
Is F99 billable?
Yes. F99 is a billable code in the FY2027 ICD-10-CM file. Use a more specific code when the record documents one.
What documentation notes apply to F99?
The CDC tabular list gives 1 Excludes1 note (not coded together) for F99 and the categories above it. They are listed on this page.
What chapter is F99 in?
Chapter 5. Mental, behavioral and neurodevelopmental disorders.
When do ICD-10-CM codes change?
Every October 1, with the new fiscal year file. Some years add April 1 updates. This page uses the FY2027 file, effective October 1, 2026.