Pathology/Lab Coding Alert

Question: Our lab performed an EIA test for Aspergillus antigen detection, but we received a denial when we billed the test as 87449. What could be the reason for the denial?

Codify Subscriber

Answer: You should always read the Claim Adjustment Reason Code (CARC) and possibly Remittance Advice Remark Code (RARC) to help understand why the payer denied a specific claim.

Without CARC information, it appears that one possible explanation for your denial is the use of a “not otherwise specified” code when a specific code exists for the procedure you’re billing. Look at the following codes to understand the discrepancy:

• 87305 (Infectious agent antigen detection by immunoassay technique, (eg, enzyme immunoassay [EIA], enzyme-linked immunosorbent assay [ELISA], immunochemiluminometric assay [IMCA]) qualitative or semiquantitative, multiple-step method; Aspergillus)
• 87449 (… not otherwise specified, each organism).

There’s more: Antigen tests aren’t the only lab tests for Aspergillus, and payers may have different expectations for diagnoses that indicate medical necessity for the different tests. For instance, clinicians may request an Aspergillus antibody test instead of an antigen test, and you’d bill that test as 86606 (Antibody; Aspergillus). The antibody test is more common as a first-line test to look for Aspergillus infection, while a specific antigen test may be indicated when clinical presentation indicates a possible severe disease state caused by the organism such as invasive aspergillosis (IA).