Pathology/Lab Coding Alert

Question: Our lab performs creatine kinase and isoenzymes to aid in diagnosis of acute myocardial infarction. Does the code for total CK include the isoenzymes?

Answer: No, if the lab measures serum creatine kinase (CK) and CK isoenzymes, you should report 82550 (Creatine kinase [CK] [CPK]; total) and 82552 (... isoenzymes). If the lab measures total CK and only the CK-MB isoenzyme, you should code 82550 and 82553 (... MB fraction only).

Elevated total CK can indicate myocardial infarction (MI), but CK isoenzyme determination can add significant diagnostic information. Samples for these tests may be taken at admission, 12 hours later, 24 hours after admission, and possibly 48 hours after admission. The timing is important because CK and isoenzyme CK-MB peak between 15-30 hours after MI symptom onset, but CK-MB disappears from the serum more rapidly than total CK.

Each time the lab performs CK total and CK isoenzymes on a unique blood draw specimen, you should bill 82550 and 82552. If repeat tests are within the same calendar day, you may need to append modifier 91 (Repeat clinical diagnostic laboratory test), depending on the payer.