Q&A: Proper reporting of laterality modifiers

Q: I am confused about the difference between the laterality modifiers -LT (left side) and -RT (right side) and modifier -50 (bilateral procedure). Can you explain?

A: There is a lot of confusion surrounding these modifiers. Unfortunately, there isn’t one comprehensive resource that addresses all the “do’s” and “don’ts” for reporting them. And there are payer differences regarding what pieces of information should be included for payment.

The initial intent of the -RT and -LT modifiers was for use in radiology, but there are many instances where they come into play for other types of services. The Medicare Claims Processing Manual, Chapter 4, section 20.6.2, states that they are to be used to identify laterality when a procedure is performed on paired organs such as the eyes, ears, or kidneys.

The -RT and -LT modifiers should be used whenever a procedure is performed on one side. For instance, when reporting CPT code 27560 (closed treatment of patellar dislocation; without anesthesia), modifier -RT or -LT should be appended if only one knee is treated.

You append modifier -50 when the procedure is performed on both paired organs during the same session (e.g., code 27560 should be reported with modifier -50 if both knees are treated). However, if the procedure is inherently bilateral, you wouldn’t append modifier -50 (e.g., 93930 [duplex scan of upper extremity, arteries or arterial bypass grafts; complete bilateral study]).

Consider the following scenario:

A child presents to the ED with a closed fracture of the left hand. A 2-view hand x-ray is performed showing a small fracture that the physician then reduces; afterward, a 1-view x-ray is taken to ensure alignment.

CPT codes used to report this service, which each include the -LT modifier to note the left hand, include:

• 73120-LT, radiologic examination, hand; two views
• 73120-LT-52, radiologic examination, hand; one view, with additional modifier to note reduced services
• 26600-LT, closed treatment of metacarpal fracture, single; without manipulation, each bone

Remember, different payers may require different coding. Some may request modifiers -RT and -LT on different line items instead of modifier -50. Other payers may want bilateral services represented on two lines with modifier -50 on the second line.

Editor’s Note: Susan E. Garrison, CHCA, CHCAS, CCS-P, CHC, CPAR, CPC, COC, and Sarah L. Goodman MBA, CHCAF, COC, CCP, FCS, answered this question during the HCPro webinar, “2018 Modifier Update: Guidance and Regulations for Hospitals.”

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