Pathology/Lab Coding Alert

Question: We cultured a septic lesion from a burn patient and identified the organism as Proteus mirabilis. The identification required biochemical tests oxidase, catalase, methyl red, indole, lysine decarboxylase and reduction of nitrate. How should we code this?
New Hampshire Subscriber  Answer: You should report the culture and the presumptive identification to Proteus sp. as 87070 (Culture, bacterial; any other source except urine, blood or stool, aerobic, with isolation and presumptive identification of isolates). The presumptive codes such as 87070 include -identification by colony morphology, growth on selective media, Gram stains or up to three tests (e.g., catalase, oxidase, indole, urease),- according to CPT.
 In your case, you further identified the organism to the species level using additional biochemical tests beyond three -quot; methyl red, lysine decarboxylase and reduction of nitrate. That means you should also report 87077 (Culture, bacterial; aerobic isolate, additional methods required for definitive identification, each isolate) for the culture.
 You should report one unit of 87077 because you-ve definitively identified one isolate to the species level.
 Pitfall: Don't make the mistake of listing 87077 x 3 just because the lab performed three additional tests for the definitive identification. The unit of service for 87077 is the isolate. Regardless of the number of methods used, such as biochemical panels and slide cultures, you should report 87077 once for each isolate that the lab definitively identifies.