The patient had a right breast ultrasound, and we billed the following CPT® code with
modifier -RT:

76641 Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; complete

The insurer denied this claim due to the modifier. Doesn’t the breast ultrasound require a modifier?


Unfortunately, modifier use is payer-specific. Each payer makes its own rules about how it wants modifiers assigned. In the case you describe above, since the payer is denying because of the modifier, you would not use modifier -RT or -LT, if you are performing a unilateral ultrasound.  Remember, if billing for the interpretation only, you must include modifier -26.

If you are performing bilateral breast ultrasound, then report the appropriate code with modifier  -50. However, note that some providers still believe that modifier 50 should not be used for radiology claims (according to previous guidance from the American Medical Association), but that has changed over the last several years. It is now a required modifier for some radiology procedures and some payers. As stated above, modifiers are payer-specific and in many cases if you want to get bilateral radiology procedures paid, you must use modifier -50.

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CPT is a registered trademark of the American Medical Association.