Gastroenterology Coding Alert

Question: Our office is having trouble distinguishing between the proper times to use modifiers -59 and -51. Would you tell us what the differences are between the two, and when we should use each one?

Nevada Subscriber Answer: Modifier -59 (Distinct procedural service) and modifier -51 (Multiple procedures) are used most commonly by gastroenterologists when coding multiple procedures, such as two endoscopies in the same session. In order to master the modifiers, coders must be familiar with each modifier and its proper use.

In general, use modifier -59 when you are reporting two codes separately that are usually bundled together, such as an upper gastrointestinal endoscopy in which the physician biopsies one lesion and cauterizes another in a separate site.

When using modifier -59, include documentation that proves that the second procedure:

 was performed during a second patient encounter or second patient session,
 was performed using a separate incision or excision on the patient, and/or
 was performed on a separate site or organ system.

You may use modifier -51 when more than one procedure is performed in the same session by the same gastroenterologist and the second service is not a component of the first.

For example, if a gastroenterologist performs a diagnostic EGD and a colonoscopy to control bleeding of a lesion in the same encounter, report 45382 (Colonoscopy, flexible, proximal to splenic flexure; with control of bleeding [e.g., injection, bipolar cautery, unipolar cautery, laser, heater probe, stapler, plasma coagulator]) and 43235 (Upper gastrointestinal endoscopy including esophagus, stomach, and either the duodenum and/or jejunum as appropriate; diagnostic, with or without collection of specimen[s] by brushing or washing [separate procedure]) with modifier -51 attached.

Most carriers and Medicare intermediaries do not require modifier -51, because their computers will automatically pick up the multiple procedures and process them according to the multiple-procedure rules.

Tip: When using either modifier -59 or -51, be sure to attach the modifier to the code with the lower relative value unit (RVU). Otherwise, you could lose out on legitimate reimbursement money. In the previous example, the RVU for 45382 is 8.24, while 43235 has an RVU of just 4.27.