Answer: You should report the bilateral study code once without any modifiers appended. For example, if you perform a bilateral duplex scan of extremity veins, you should report one unit of CPT 93970 (Duplex scan of extremity veins including responses to compression and other maneuvers; complete bilateral study). Medicare carriers reimburse practices about $175 for one unit of 93970. Most payers reimburse about $125 for each unit of CPT 93971 (Duplex scan of extremity veins including responses to compression and other maneuvers; unilateral or limited study). Therefore, some practices try inappropriately to increase their reimbursement by reporting 93971 with a bilateral modifier, hoping to exceed the $175 that they would recoup for 93970. You should never attempt to game the system this way. It is not legal and is certainly not considered correct coding.