A modifier provides the means by which the reporting physician or provider can indicate that a service or procedure that has been performed has been altered by some specific circumstance but not changed in its definition or code.
Level I modifiers are codes and descriptors copyrighted by the American Medical Association's current procedural terminology (CPT).
Level II modifiers are codes and descriptors approved and maintained jointly by the alpha-numeric editorial panel (consisting of CMS, the Health Insurance Association of America, and the Blue Cross and Blue Shield Association).
| Modifier | Description | Effective | |
|---|---|---|---|
| F1 | Left hand, second digit | Jan 01, 1999 | |
| F2 | Left hand, third digit | Jan 01, 1999 | |
| F3 | Left hand, fourth digit | Jan 01, 1999 | |
| F4 | Left hand, fifth digit | Jan 01, 1999 | |
| F5 | Right hand, thumb | Jan 01, 1999 | |
| F6 | Right hand, second digit | Jan 01, 1999 | |
| F7 | Right hand, third digit | Jan 01, 1999 | |
| F8 | Right hand, fourth digit | Jan 01, 1999 | |
| F9 | Right hand, fifth digit | Jan 01, 1999 | |
| FA | Left hand, thumb | Jan 01, 1999 | |
| FB | Item provided without cost to provider, supplier or practitioner, or full credit received for replaced device (examples, but not limited to, covered under warranty, replaced due to defect, free samples) | Jan 01, 2008 | |
| FC | Partial credit received for replaced device | Jan 01, 2008 | |
| FP | Service provided as part of family planning program | Jan 01, 2005 | |
| FQ | The service was furnished using audio-only communication technology | Jan 01, 2022 | |
| FR | The supervising practitioner was present through two-way, audio/video communication technology | Jan 01, 2022 | |
| FS | Split (or shared) evaluation and management visit | Jan 01, 2022 | |
| FT | Unrelated evaluation and management (e/m) visit on the same day as another e/m visit or during a global procedure (preoperative, postoperative period, or on the same day as the procedure, as applicable). (report when an e/m visit is furnished within the global period but is unrelated, or when one or more additional e/m visits furnished on the same day are unrelated) | Jan 01, 2022 | |
| FX | X-ray taken using film | Jan 01, 2017 | |
| FY | X-ray taken using computed radiography technology/cassette-based imaging | Jan 01, 2018 | |
| G0 | Telehealth services for diagnosis, evaluation, or treatment, of symptoms of an acute stroke | Jan 01, 2019 | |
| G1 | Most recent urr reading of less than 60 | Jan 01, 1998 | |
| G2 | Most recent urr reading of 60 to 64.9 | Jan 01, 1998 | |
| G3 | Most recent urr reading of 65 to 69.9 | Jan 01, 1998 | |
| G4 | Most recent urr reading of 70 to 74.9 | Jan 01, 1997 | |
| G5 | Most recent urr reading of 75 or greater | Jan 01, 1998 |