Ask Dr. Z

We have a patient who presented for an ultrasound-guided breast biopsy. This was based on prior mammogram and ultrasound showing breast asymmetry. The prescan for the biopsy showed no discrete finding for biopsy. We would normally charge/code for the intended procedure and attach either -73 or -74 modifier; however, the physician then ordered additional mammographic images to further evaluate. Would you recommend charging for the US-guided breast biopsy with the -73 modifier based on the reason the patient presented and original order? Would you also charge the patient for the mammogram unilateral? Or would you only charge the patient for the complete unilateral mammogram?