In the coding world, modifiers are two-digit symbols added to CPT procedure codes to signify the procedure has been altered in some way. Medicare and many payers accept modifiers. However, proper use can be confusing since not all payers require modifiers to be used the same way. According to Current Procedural Terminology (CPT) guidelines, not using required modifiers when necessary can cause unnecessary claim denials. Modifiers that affect reimbursement, for instance -59, are sequenced before those that are informational only, such as -RT.