MODIFIERS - CPT The CPT system contains thirty-one modifiers.  Modifiers –50 (bilateral), -52(when used to indicate a discontinued procedure), -53, -73, and –74 apply only to surgical procedures.  General guidelines for using modifiers appear in the form of questions to be considered.  If the answer to any of the following is yes, then it is appropriate to use the applicable modifier.· Will the modifier add more information regarding the anatomic site of the procedure?· Will the modifier help to eliminate the appearance of duplicate billing?· medical coding training fcouses on these in detail.