Pediatric Coding Alert

Question: A young patient with type 1 diabetes described feeling weak and unsteady. The pediatrician administered a glucose test, which showed the patient was hypoglycemic. The pediatrician then gave the patient a glucose gel, and 15 minutes later administered a second glucose test. This time, the test showed that blood sugar levels were back to normal. Do I code both tests?

Arkansas Subscriber

Answer: Code this encounter using the appropriate lab test code, such as 82947 (Glucose; quantitative, blood (except reagent strip)), on two lines, appending modifier 91 (Repeat clinical diagnostic laboratory test) to the lab test code on line 2. The modifier tells the payer that it’s medically necessary to do the lab more than once in a day.

Keep in mind that you only use modifier 91 on the second test, and it’s only necessary when the results of both tests are needed. If the first test used an insufficient amount of blood, or the sample was contaminated, then do not bill as a repeat lab. You may want to consult the payer and the practice manager about policies on user error; but in situations where a second test is necessary because of a mistake made in preparing the first test, you should generally bill for only one test.