Gastroenterology Coding Alert

Question: My colleague and I have been debating the proper times to use modifiers 59 and 51. What are the differences between the two, and when should we use each one?

Nevada Subscriber Answer: As a gastroenterology coder, you would use modifiers 59 (Distinct procedural service) and 51 (Multiple procedures) most commonly when coding multiple procedures, such as two endoscopies in the same session. To master the modifiers, you must be familiar with each modifier and its proper use.

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

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

- during a second patient encounter or second patient session,

- using a separate incision or excision on the patient, and/or

- on a separate site or organ system. You may use modifier 51 when the same physician performs more than one procedure during the same session 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 during 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 appended.

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 append the modifier to the code with the lower relative value. Otherwise, you could lose out on legitimate reimbursement.

Be aware: You have one GI code for which this method does not apply. Anytime your gastroenterologist performs 45382 (Colonoscopy ... with control of bleeding) during the same session as any other colon family code (biopsy, hot biopsy or snare), you should add modifier 59 to 45382. Payers will always bundle this code into any other code you bill. Payer perception is that the physician caused the bleeding while performing the other procedure. By placing modifier 59 on 45382, you are saying not to bundle this code because the physician did not cause the bleeding -- the bleeding occurred at a different site.