Pathology/Lab Coding Alert

Question: Our lab performed two troponin tests four hours apart, as well as a creatine kinase and a CKMB isoenzyme test to evaluate a patient with suspected heart attack. How should we code the tests?

Ohio Subscriber

Answer: You don’t mention whether you perform a qualitative or quantitative troponin assay, which would lead you to choose one of the following two codes:

• 84484, Troponin, quantitative
• 84512, Troponin, qualitative.

Additionally, you should report the creatine kinase (CK) test and the test for the CKMB isoenzyme using the following two codes:

• 82550, Creatine kinase (CK) (CPK); total
• 82553, ... MB fraction only.

Repeat test: If you repeated the same troponin test four hours apart, you should append modifier 91 (Repeat clinical diagnostic laboratory test) to the second unit of the test code, whether 84484 or 84512.

Physicians may order several different blood tests to aid in the diagnosis of myocardial infarction (MI), but the troponin test is probably the most common. You won’t find any Correct Coding Initiative (CCI) restrictions on billing these different tests together, even though clinicians may use the various tests for similar diagnostic information.