Pathology/Lab Coding Alert

Question: Our lab carries out an influenza A/B test using a commercial kit called ZstatFlu Test. Which influenza code should we use to report this service, 87400 or 87804? North Carolina Subscriber Answer: Select the proper code for an influenza test based on the test method used. ZstatFlu Test provides, based on enzyme activity, a qualitative determination of the presence of either influenza A or B, but it does not distinguish between the two types. Neither of the codes you mention describes this test. Code 87804 (Infectious agent antigen detection by immunoassay with direct optical observation; Influenza) is not the appropriate code because it does not describe an enzyme test.

Code 87400 (Infectious agent antigen detection by enzyme immunoassay technique, qualitative or semiquantitative, multiple step method; Influenza, A or B, each) describes an enzyme immunoassay (EIA) test that can provide separate determinations for influenza A or B antigens. Although the ZstatFlu uses EIA methodology, you should not report it as 87400 because it does not distinguish between type A and B. Rather, you should report this test with the nonspecific EIA code: 87449 (Infectious agent antigen detection by enzyme immunoassay technique, qualitative or semiquantitative; multiple step method, not otherwise specified, each organism).