Pathology/Lab Coding Alert

Question: An emergency room physician ordered a test for a suspected acetaminophen overdose. Our lab performed a test using liquid chromatography mass spectrometry (LC-MS) to identify acetaminophen and metabolites. Should we report the new (2021) acetaminophen code?

Alabama Subscriber

Answer: No, in this instance, you should not report the therapeutic drug assay code 80143 (Acetaminophen). Instead, the definitive drug test code 80329 (Analgesics, non-opioid; 1 or 2) would be more appropriate.

According to CPT^® guidelines, tests in the CPT^® Therapeutic Drug Assay section serve the function of monitoring levels of known medications in the patient specimen such as blood, while definitive drug tests are used to identify and distinguish drugs and their metabolites in a specific drug class. But choosing the code based on the “purpose” may be confusing at times.

CPT^® also designates the lab methods represented by definitive drug test codes, such as liquid chromatography mass spectrometry (LC-MS), but specifies not to use the codes for immunoassay and enzymatic methods.

In the case you describe both the purpose and the lab method more closely fit the 80329 descriptor.