Tips for Modifiers use in an Ambulatory Surgery Center

Some of the most common modifiers used in the ASC are:

Modifier 50: Bilateral Procedure Unless otherwise identified in the listings, bilateral procedures that are performed in the same operative session should be identified by adding modifier 50 to the appropriate five-digit CPT code. This modifier is reported for procedures/ services that are performed on both sides of the body at the same operative session (mirror image). The policies each payer has for the use of modifier 50 vary widely, so be sure and check with each carrier before use. The modifier is applied to the CPT code, which is billed once even though the procedure was performed on two sides. For example, a 22-year-old skier injures both right and left knees, with peripheral longitudinal tears of both medial and lateral menisci and underwent arthroscopic meniscus repair of both knees by a suture technique. Appropriate reporting would be 29883-50.

Do not use modifier 50 if the procedure is designated inherent bilateral, which means the code descriptor indicates bilateral in the description. (Example: 58600 ligation or transaction of fallopian tube(s), abdominal or vaginal approach, unilateral or bilateral). Determination of pricing for a bilateral procedure would be identical to the determination of pricing in multiple procedures for CMS: 100 percent for the first procedure and 50 percent for the second procedure.

Note that some carriers prefer the use of modifiers LT and RT instead of modifier 50. In this case, the CPT code would be reported twice, as in 29883-LT and 29883-RT. Check with each carrier to ensure you are billing appropriately.
HCPCS Level II Modifier LT and RT: Modifiers LT and RT apply to codes that identify procedures that can be performed on paired organs such as ears, eyes, nostrils, kidneys, lungs, and ovaries. Modifier LT (left) and RT (right) are usually applied when a procedure is performed on only one side. ASCs use the appropriate modifier to identify which one of the paired organs was operated on. CMS requires these modifiers whenever appropriate.

For example: 66984 RT cataract surgery on the right eye. If these modifiers are not used, the carrier may assume that the second procedure done on the opposite eye is a duplicate service and may deny payment.