In HCPCS Level II coding, two alpha digits, two alphanumerical characters, or a single alpha digit placed after the usual five-digit CPT procedure code number. These modifiers are used to identify situations that change the description of service or supply. They are accepted by insurance carriers nationally and are updated annually by the Centers for Medicare and Medicaid Services (CMS) (see Box H-2 and Figure H-1 ).Box H-2HCPCS MODIFIERSWhen taking x-ray films of both feet, the billing portion of the insurance claim appears as follows:05/06/XX73620 RT Radiologic examination, foot—right05/06/XX73620 LT Radiologic examination, foot—left HCPCS Level II alpha modifiers (LT and RT used to identify left and right hands) and alphanumerical modifiers (FA through F9) used to identify digits (fingers) of left and right hands.