Pathology/Lab Coding Alert

Make sure you understand the lab method and source

Not all influenza tests are created equal. You need to know the specimen and test technique to select the correct code--every time.

Learn Influenza Code Choices

Your lab might identify infection with influenza A and/or B virus using any of the following tests. Look at the description of specimen source and lab method to help you choose the proper code for the test your lab performs:

- 86710--Antibody; influenza virus

The specimen is blood, and the test may show infection with influenza A or B or both. Presence of IgG antibody shows previous exposure to the virus, while IgM antibody presence shows current acute infection. The method may be enzyme-linked immunosorbent assay (ELISA) or other methods. The key is that this is an antibody test, not an antigen test.

- 87275--Infectious agent antigen detection by immunofluorescent technique; influenza B virus

- 87276--- influenza A virus

These two tests--one for influenza A and one for influenza B antigen detection--use direct fluorescence antibody (DFA) methodology to detect the infecting organism in respiratory tract swabs or other direct sources.

- 87400--Infectious agent antigen detection by enzyme immunoassay technique, qualitative or semiquantitative, multiple-step method; influenza, A or B, each

The lab may perform this antigen test on several sources, such as blood, nasopharyngeal wash, throat swab or sputum. The method is enzyme immunoassay (EIA). Because this single code is for influenza -A or B, each,- you should report two units of 87400 if your lab identifies A and B.

- 87449--Infectious agent antigen detection by enzyme immunoassay technique qualitative or semiquantitative; multiple-step method, not otherwise specified, each organism

Sources and methodology for 87449 are similar to sources and methodology for 87400.

Question: Why would you use a -not-otherwise-specified- code for influenza A or B by EIA when 87400 is a specific code for influenza A or B by EIA?

Answer: Because sometimes an EIA test does not distinguish between influenza A or B, so you can't report 87400, which is for -A or B, each.-

For instance: The ZymeTx Zstatflu Test provides a qualitative determination of influenza A and B from throat swab by EIA--but it does not distinguish between A and B. That means you should report the test with 87449 instead of 87400.

- 87804--Infectious agent antigen detection by immunoassay with direct optical observation; influenza

The specimen source for this test is nasopharyngeal swab, nasal wash or nasal aspirate. The methodology is direct optical observation. Although the code does not mention influenza A or B, commercial tests such as Binax NOW A&B Test can provide two separate results--one for type A and one for type B. Report the code twice if your lab provides results for influenza A and influenza B.  

Use modifier 59 to indicate that the second test is separate from the first, says Deb Chandler, BA, CPC, ACS-FP, CCP, with Family Physician Associates in Columbus, Ohio. Read more about how to report both flu tests in -Code 87804--Once or Twice? You Could Save an Extra $17- included in this issue.

Don't Miss Modifier QW

CLIA lists several of these tests for use by waived-status labs. If your lab operates under a certificate of waiver and you perform one of the waived tests, you should list the code with QW (CLIA waived test). The waived influenza procedures include some commercial tests that you would report as 87804 or 87449.