The Right (and Left) Time to Bill Modifier 50
Modifier 50 Bilateral procedure can sometimes cause confusion because of the seemingly redundant anatomical modifiers RT (right) and LT (left). Although these modifiers may seem interchangeable, they are not.
Bilateral surgery is defined as a procedure performed on both sides of the body at the same operative session or on the same day that is not otherwise identified in its code descriptor as “bilateral” or “bilateral or unilateral.” Medicare and payers that follow Medicare rules require the code for such a procedure to be billed on a single claim line with modifier 50 appended, and one unit of service.
The American College of Surgeons offers this scenario:
A 68-year-old female undergoes stereotactic needle biopsy of an area of suspicious microcalcifications in the left and right breasts that reveals ductal carcinoma in situ. Review of the mammogram shows the areas biopsied are part of an extensive area of suspicious calcifications extending over a 7-centimeter area along a ductal distribution in each breast. Following review of surgical alternatives with the patient, and considering especially the patient’s breast size relative to the extent of the calcifications, a bilateral mastectomy is planned.
19303–50, Mastectomy, simple, complete, Units = 1
Remember: Certain codes are subject to the bilateral payment rule. Check the code’s procedure indicator number in the Medicare Physician Fee Schedule.
Modifiers RT and LT should not be used when modifier 50 applies. Use these modifiers to identify which side(s) of contralateral anatomic sites (e.g., bones, joints), paired organs (e.g., kidneys, lungs), or extremities (e.g., legs, arms) were operated on for procedures identified in their associated code descriptors as “bilateral” or “unilateral or bilateral.”
Not all payers follow Medicare rules, so always check your payer contracts for specific guidance.
Sources: WPS Medicare; First Coast Service Options, Inc.; CMS Internet-only manual (IOM) Pub. 100-04 Medicare Claims Processing Manual, Chapter 4, Section 20.6.2; Bulletin of the American College of Surgeons, Jackson, Mabry, Savarise, October 1, 2013