Do anyone know the appropriate code for Elevated CPK (Creatine Phosphokinase)? I believe it is a serum enzyme blood test to detect damage to the heart muscle and skeletal muscles? The physcian did a muscle BX deep, in which I coded this as a 20205. The physcian diagnosed the patient with elevated CPK and back pain, according to the general surgery coding companion, niether of these dx are covered. The path report came back as no diagnostic abnormality.