Internal Medicine Coding Alert

Question: A patient presented to receive a glucose blood test using a reagent strip (82948). The first time we tested the patient, his sugar was too low, so we gave him some crackers and a drink. In a little while we gave him the glucose blood test again. How should we report both tests?


Nebraska Subscriber


Answer: Medicare and CPT guidelines call for you to report 82948 (Glucose; blood, regent strip) twice and attach modifier -91 (Repeat clinical diagnostic laboratory test) to the second code. You should use modifier -91 on the second code because the internist treated the patient after the initial test, and then repeated the glucose test following the treatment.

Correct coding: According to the Medicare Carriers Manual (MCM), you may use modifier -91 "to indicate that a test was performed more than once on the same day for the same patient, only when it is necessary to obtain multiple results in the course of treatment." 

Important: Don't use modifier -91 when the physician retests a patient to confirm initial results, even if the physician has testing problems with the specimens or equipment, the MCM says.