Gastroenterology Coding Alert

It's imperative that patients undergo a variety of diagnostic tests before a physician chooses surgical treatment for their gastroesophageal reflux disease (GERD), so coding for these tests needs to become a reflex to you.

GERD is a digestive disorder that affects the lower esophageal sphincter (LES), which functionally separates the esophagus and the stomach. Individuals with GERD experience heartburn because the malfunctioning LES allows the stomach's contents to flow back or reflux into the esophagus. Usually, the physician treats symptoms with medication, but sometimes surgery is required for serious cases. Before surgery, however, it is important for the physician to run a battery of diagnostic tests that will help to determine whether the patient is a good candidate for surgery. Incorrect coding for these common procedures can lead to payment problems.

Coders often get confused when their physician documents an "acid reflux study" or a "gastric motility study," since these phrases are ambiguous at best. In reality, there are two basic types of motility studies: gastric or esophageal manometry, and pH monitoring. The physician uses esophageal manometry to evaluate neuromuscular disorders of the esophagus. He places a small catheter with water flowing through it into the esophagus and the stomach. Apressure profile of the lower esophageal sphincter is taken at half-inch intervals as the doctor withdraws the catheter.

During a pH study, the physician passes a catheter probe through the nose and down to the distal esophagus. Acassette attached on the other end of the probe records the extent of the acid reflux. After he activates the cassette, the patient is sent home for a usual period of 24 hours for monitoring. The newer Bravo pH Monitoring System involves the intranasal or intraoral placement of a small capsule-size probe into the wall of the esophagus where it transmits data to a small receiver that the patient wears.

You report the first type of study using motility study codes 91010-91020. You will most commonly see 91010 (Esophageal motility [manometric study of the esophagus and/or gastroesophageal junction] study).

Report 91032 (Esophagus, acid reflux test, with intraluminal pH electrode for detection of gastroesophageal reflux) and 91033 (... prolonged recording) for 24-hour pH monitoring services. Confusion seems to arise concerning the time factor with this service. The general standard for esophageal acid reflux tests is 24-hour monitoring. You should report 91033 for this 24-hour monitoring. Use 91032 for tests that last less than 24 hours.

A nurse or technician usually performs both of these services, and the gastroenterologist interprets the results, says Susan Gruber, CPC, billing manager at a gastroen-terological practice in Hagerstown, Md. But there are technical and professional components to these codes. This ends up being a sticking point for many coders. Gruber recently spoke to Medicare on the issue and received information that if you bill for both aspects, then they assume you own the equipment. The technical component (-TC) represents ownership and maintenance of the equipment, while the professional component (-26) represents the gastroenterologist's interpretation of the test results.

Gastroenterologists perform a majority of these tests in a hospital setting or ambulatory surgical center, so in those cases you should append modifier -26 to the procedure code. However, if the gastroenterologist practice owns the equipment, you can bill the global code without any modifiers. For the physician's services to qualify as interpretations, he must record the findings in a separate report that is kept in the patient's records. Also, he must sign the test.

It is not unusual for a gastroenterologist to perform the manometric test first and then insert the probe for the pH study on the same day. Many practices report both services on the same day without using any modifiers and receive full reimbursement, although payment may vary from payer to payer.

According to Gruber, you should be able to be reimbursed for these procedures on the same day. They are not bundled, so you do not need to apply modifier -59 (Distinct procedural service) to either code. Some coders may use modifier -51 (Multiple procedures) on the lesser-valued procedure, but you should simply check with your local carrier to get specific coding and payment information. Kimberly Green, CPC, project coordinator at the University of Pittsburgh Physicians, does not recommend using modifier -51 simply because most payers automatically apply it on multiple procedures on the same day.

Although some practices bill for both tests on the same date of service without any reimbursement problems, many others use the date of service for the pH study as the day the test is completed. This sidesteps any problems you might have with billing on the same date of service. Also, this ensures that the physician completes the test before you bill for it. Green, however, finds no payment problems in reporting pH monitoring on the date of service it was begun because she waits to enter the charge until the test is completed and interpreted.

In addition to these procedures, the physician may perform other aspects of an E/M visit. "If the decision to do the motility study was not made prior to the patient's visit, then we bill the visit and the procedure on the same day," Green says. Although this does not happen often, she does not remember receiving any denials for the service.

Gruber agrees that if the office visit is a separate service, then you should append modifier -25 (Significant, separately identifiable evaluation and management service by the same physician on the same day of the procedure or other service) to the E/M service code.

Say a gastroenterologist sees a patient for heartburn. He performs an expanded, problem-focused history and examination with straightforward decision-making. He orders several lab tests and discusses diagnostic and treatment options with the patient. In conjunction with these services, the gastroenterologist orders the pH study and manometry to determine whether the patient is a good candidate for further surgical treatment. You would code the following: