Gastroenterology Coding Alert

Question: What is the -GY modifier, and how do you use it?

Oregon Subscriber

Answer: Modifier -GY is a voluntary code that was created by the Centers for Medicare and Medicaid Services (CMS) in 2002, designed to use on claims for noncovered services.

Use modifier -GY (Item or service statutorily excluded or does not meet the definition of any Medicare benefit) when a claim will be denied because Medicare is legally forbidden to pay for one of the services. (The services Medicare cannot legally cover are marked with an "N" status code on the Medicare fee schedule.) For example, say an asymptomatic 60-year-old patient wants to have a screening colonoscopy, but he had one four years ago and Medicare will only pay for one every decade.

If the patient insists on having the colonoscopy, report G0121 (Colorectal cancer screening; colonoscopy on individual not meeting criteria for high-risk) with modifier -GY attached to show that your office is aware that Medicare will not pay for the service.

The -GY modifier is not mandatory, but Medicare fast-tracks -GY modifier claims to denial -- and the faster your office receives the denial, the quicker you can bill the patient or secondary insurance for the balance.