| RA | Replacement of a dme, orthotic or prosthetic item |
| RB | Replacement of a part of a dme, orthotic or prosthetic item furnished as part of a repair |
| RC | Right coronary artery |
| RD | Drug provided to beneficiary, but not administered "incident-to" |
| RE | Furnished in full compliance with fda-mandated risk evaluation and mitigation strategy (rems) |
| RI | Ramus intermedius coronary artery |
| RR | Rental (use the 'rr' modifier when dme is to be rented) |
| RT | Right side (used to identify procedures performed on the right side of the body) |