No more 'complex medical review' for these non-covered services. Most of the time, when Medicare payers process denials in a speedy fashion, that's bad news for your practice -- but when you're using modifier GZ, you are already expecting a denial. CMS has made that happen faster with a new regulation indicating that all claims with modifier GZ appended will be denied immediately. Background on why you'll use GZ: If you should have had a patient sign an advance beneficiary notice (ABN) but failed to do so, you should append modifier GZ (Item or service expected to be denied as not reasonable and necessary) to the CPT code describing the noncovered service the physician provided. The advantage to reporting modifier GZ is to avoid the potential for fraud and abuse charges -- by appending this modifier, you're telling Medicare that you know you performed a noncovered service and you know they aren't going to pay for it. What the new rule means: In black and white: Plan ahead: