F4HCPCS Level II
Left hand, fifth digit
- Usage notes
- Append to procedure codes performed on the left hand, fifth digit (little finger).
- Common mistakes
- Selecting F4 (left) when the note documents F9 (right) — a common left/right transposition error.
Related modifiers
Frequently asked questions
What does modifier F4 mean?
Left hand, fifth digit
When do I use modifier F4?
Append to procedure codes performed on the left hand, fifth digit (little finger).
What's a common mistake with modifier F4?
Selecting F4 (left) when the note documents F9 (right) — a common left/right transposition error.
HCPCS modifier data from CMS. CPT® is a registered trademark of the American Medical Association — CPT modifier descriptions are not included on this site. Always verify codes with authoritative sources before making billing decisions.