Pathology/Lab Coding Alert

Question: If we’re performing 85610 and 80061 in a physician-office lab, should we use modifier QW or 90? Is QW only for Medicare?

Tennessee Subscriber

Answer: If the physician-office lab operates with a certificate of waiver from under the Clinical Laboratory Improvement Amendments (CLIA), then you should report the codes with modifier QW (CLIA waived test).

Modifier QW indicates that a specific, commercially marketed in vitro diagnostic test has been categorized by the Food and Drug Administration (FDA) as a waived test. That means that the test involves a simple, accurate lab procedure with negligible likelihood of erroneous results that poses no reasonable risk of harm to the patient if performed incorrectly.

Modifier 90 (Reference [outside] laboratory) means that the test was performed by an outside reference lab, which is not the case you describe in your question.

The two tests that you mention, 85610 (Prothrombin time) and 80061 (Lipid panel), both appear on the list of CLIA waived tests with modifier QW. If your lab performs one of the approved kits or methods (such as Roche Diagnostics CoaguChek XS for 85610 or Alere Cholestech LDX for 80061) and operates with a CLIA certificate of waiver, you should bill Medicare and other payers using 85610QW and 80061QW.

You can find a complete list of CLIA waived test codes, including a list of the approved commercially marketed tests at www.cms.gov/Regulations-and-Guidance/Legislation/CLIA/Categorization_of_Tests.html. Download the list of waived tests for the current list, which is updated quarterly.