Pediatric Coding Alert

Question: An insurance company recommended we code influenza test A+B as 87804-QW and 87804-QW-91. Should I use modifier 51 instead, which seems more appropriate than modifier 91?


Illinois Subscriber
Answer: You should follow the insurer's directive and report rapid influenza test A as 87804-QW (Infectious agent antigen detection by immunoassay with direct optical observation; influenza; CLIA waived test) and test B with modifier 91 (Repeat clinical diagnostic laboratory test) appended to 87804-QW. Although the payer's coding instructions are technically incorrect, submit claims as the company directs, if you have written documentation of the inappropriate request.

Example: Some insurers request in writing that physicians use the counseling codes (99401-99402, Preventive medicine counseling and/or risk factor reduction intervention[s] provided to an individual [separate procedure]) for well checkups (such as new patient preventive medicine services 99381-99385 or established patient preventive medicine services 99391-99395). Although this coding contradicts CPT, if an insurer makes that ruling and reimburses the service that way, you should accept the request.

Warning: Don't code inappropriately based on a verbal request. The insurer could not honor the coding in the future and challenge your method.In your case, however, the CPT modifier that you or the payer suggests is not correct.

Why: You should use modifier 91 when you have to repeat a lab test during the same visit to obtain subsequent test results, such as hemoglobin levels. The rapid
influenza test B is a different lab test, not a repeat lab test. Each test instead detects a different type of influenza antigen: A and B. Therefore, attaching modifier 91 to 87804-QW doesn't correctly describe why you're performing the second test.

You don't, however, have to append modifier 51 (Multiple procedures) to the influenza B test. Because the National Physician Fee Schedule does not subject laboratory codes to multiple-procedure rules, 87804 is exempt from modifier 51. Therefore, some insurers recommend that you report influenza test A+B with two units (in other words, 87804-QW x 2).