Gastroenterology Coding Alert

Question: My gastroenterologist performed an esophageal function test. How should I report this, and how is this procedure different from an esophageal motility study?


Maine Subscriber


Answer: Although both esophageal motility study and esophageal function testing use a nasal catheter, the esophageal function test is more sensitive and measures more things than a motility test (91010-91012).

Breakdown: Function test codes 91037 (Esophageal function test, gastroesophageal reflux test with nasal catheter intraluminal impedance electrode[s] placement, recording, analysis and interpretation) and 91038 (... prolonged [greater than 1 hour, up to 24 hours) represent monitoring all reflux, both acid and non-acid. In contrast, motility studies (91010-91012) measure only esophageal muscular activity.

As the 91037-91038 descriptors indicate, you should apply these codes according to how long the monitoring test lasts. Reserve 91037 for testing that lasts as long as one hour, and use 91038 if testing lasts more than an hour.

You should not report both 91037 and 91038 for the same test because 91037 doesn't represent the first testing hour and 91038 isn't for additional time, as with some CPT add-on codes. Instead, you should apply only a single code to report the entire testing session.

Example: Your gastroenterologist inserts a nasal catheter to record esophageal impedance and muscle function for a patient who complains of frequent and painful heartburn. The physician leaves the monitor in place until the next day, or approximately 24 hours. For this service, you should report one unit of 91038.