Pediatric Coding Alert

Question: If our practice tests in the office a rapid flu test for both strains A and B, can we bill 87804 twice for the same test? If not, how should it be billed?

Codify Subscriber

Answer: The answer depends on your insurer’s policy, but in lieu of a written directive from your payer, you should definitely report the flu test code (87804, Infectious agent antigen detection by immunoassay with direct optical observation; influenza) twice.

Reporting tip: Many Medicaid states require you to follow Medicare modifier guidelines and append modifier QW (CLIA-waived test) to 87804. To keep coding uniform, many practices use modifier QW regardless of payer.

If you use a product that differentiates between influenza A & B and the physician documents both results, you should report 87804 twice. Many carriers allow you to report 87804 x 2 without a problem, because the MUEs (medically unlikely edits) that Medicaid and some other payers utilize to auto-deny second and subsequent line items limits you to two units of 87804. This means that your carrier will process two units of the code but would most likely auto-deny three or more units billed together.

For payers that do not recognize two units of 87804 and deny the second charge as a duplicate, use modifier 59 (Distinct procedural service) on the second 87804 entry. This modifier indicates that a different test was performed to test for a distinct strain. Therefore, you would report 87804-QW with one unit and 87804-59 for the second unit to these insurers.

Why not 91? In some rare cases such as certain state Medicaid providers, you may be advised by your payer to use modifier 91 (Repeat clinical diagnostic laboratory test) on the second listing of 87804. However, before using this coding method, which contradicts current coding guidelines, obtain a written recommendation from the payer.

The May 2009 CPT® Assistant backs up the advice that modifier 59 is a better option than modifier 91, stating, “Use modifier 59 when separate results are reported for different species or strains that are described by the same CPT® code. This advice should serve to clarify the use of the modifier in these instances. As a matter of differentiation, modifier 91 is used when, in the course of treating a patient, it is necessary to repeat the same laboratory test on the same day to obtain subsequent test results.”