Revenue Cycle Insider

Question: When our practice tests one patient for flu A and flu B simultaneously, we bill 87804 [Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; Influenza] for the combination. Should I be appending modifier 76 or modifier 91 to show that the “double” testing for influenza is not an error?

Michigan Subscriber

Answer: While appending a modifier might make sense, the modifiers you mention, modifier 76 (Repeat procedure or service by same physician or other qualified health care professional) or modifier 91 (Repeat clinical diagnostic laboratory test), probably wouldn’t be correct, because they’re usually used to show that an initial test was not successful, or to show that repeated testing must be performed to land on a definitive diagnosis.

Instead, look to modifier 59 (Distinct procedural service). CPT^® Assistant, May 2009; Volume 19: Issue 5 says: “Code 87804 [Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation; Influenza] is reported twice because two separate, distinct analyses are performed, providing two separate test results, one for influenza virus A and one for influenza virus B. Certain payers may require the use of modifier 59 [Distinct procedural service] when the same CPT^® code is used; alternatively, the payer may require use of the units box on the claim form.”

Remember, you need to know how your respective payer wants claims to be billed, and you should check their specific policies to see whether appending modifier 59 would be appropriate.

Rachel Dorrell, MA, MS, CPC-A, CPPM, Development Editor, AAPC