Question: Encounter notes indicate that the surgeon performed open treatment of multiple rib fractures on a patient: two ribs on the left side, and three ribs on the right side. How should I report this encounter? Montana Subscriber Answer: You might be tempted to report the fracture fixes with bilateral modifiers RT (Right side) and LT (Left side). Don’t do it. Why? There are instructions from CPT® that say you should report 21811 (Open treatment of rib fracture(s) with internal fixation, includes thoracoscopic visualization when performed, unilateral; 1-3 ribs) with modifier 50 (Bilateral procedure) appended to indicate that it was a bilateral procedure, when appropriate. Explanation: The 21811-50 coding strategy can represent a total of six ribs: three on the left side and three on the right side. Encounter notes indicate that the surgeon repaired two ribs on the left side and the three ribs on the right side, which confirms that this is the correct coding route.