Gastroenterology Coding Alert

Question: My gastroenterologist did an impedance test to examine a patient’s esophageal function. It took exactly one hour. Do I report 91037 or 91038?

Minnesota Subscriber

Answer: For a one-hour impedance test, report 91037 (Esophageal function test, gastroesophageal reflux test with nasal catheter intraluminal impedance electrode(s) placement, recording, analysis and interpretation). Here’s why:

As you’ve pointed out, when reporting esophageal function (impedance) tests, you have two main codes to consider: 91037 and 91038 (… prolonged (greater than 1 hour, up to 24 hours)).

Even though 91037 doesn’t specifically mention a measurement of time, the time distinction is made in the descriptor for 91038. To select the correct code, use that one-hour mark.

If the procedure took exactly one hour, it’s easy to second-guess yourself and think 91037 could be anything less than an hour, and 91038 anything more than an hour. That logic essentially loses the one-hour measurement of time entirely, however. Code 91038 says “… greater than 1 hour …,” so it’s safe to say 91037 includes all procedure times up to and including one hour.