Modifier 50

Bilateral Procedure


When performing a procedure on bilateral body parts, append payment modifier 50 to the appropriate code performed at the same session. The bilateral adjustment is inappropriate for (a) physiology or anatomy codes or (b) code descriptor that specifically states it is a unilateral procedure and there is an existing bilateral procedure code.

Correct Use

  • One line appending modifier 50 or RT and LT using one unit of service
  • See Bilateral Surgery Rules within Medicare Physician Fee Schedule (MPFS) Indicator Descriptions

Incorrect Use

  • Inappropriate to apply an already "bilateral description" code
  • Do not append to procedures for midline organs such as bladder, uterus, esophagus or nasal septum
  • Inappropriate to report when performed on different areas of same side of body

Claim Coding Example

Treatment Description CPT/Modifier
Total Knee Arthroplasty 27447 50




Last Updated Dec 09 , 2023