CPT modifier used for multiple procedures. When multiple procedures, other than E/M services, are performed at the same session by the same provider, the primary procedure or service may be reported as listed. The additional procedure(s) or service(s) may be identified by adding the modifier -51 to the additional procedure or service code(s). This modifier should not be appended to designated “add-on” codes (see Appendix E of CPT). Always list the procedure of highest dollar value first.