Question: Our lab performed a standard stool culture with additional plates as follows: Campylobacter media, a CIN agar selective for Yersinia, and a TCBS agar selective for Vibrio. After findings negative for Salmonella, Shigella, Campylobacter and Vibrio but positive for Yersinia spp., the lab performed additional biochemical panels and identified the organism as Yersinia enterocolitica. How should we code this? Idaho Subscriber Answer: Regardless of whether the findings are positive or negative for any given organism, you should report the tests that the lab performs. CPT provides a separate code for Salmonella and Shigella, so you should report that plate as 87045 (Culture, bacterial; stool, aerobic, with isolation and preliminary examination [e.g., KIA, LIA], Salmonella and Shigella species). For each additional organism that the lab plates for presumptive identification -- Campylobacter, Yersinia and Vibrio -- report one unit of 87046 (Culture, bacterial; stool, aerobic, additional pathogens, isolation and presumptive identification of isolates, each plate). Either report 87046 x 3 or use modifier 59 (Distinct procedural service) or modifier 91 (Repeat clinical diagnostic laboratory test), depending on your payer's reporting requirements. You should report the additional biochemical panels for definitive identification to the species level (Yersinia enterocolitica) using 87077 (Culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate). -- Reader Questions were prepared with the assistance of R.M. Stainton Jr., MD, president of Doctors- Anatomic Pathology Services in Jonesboro, Ark.