gz modifier

In medical billing, the GZ modifier is used to indicate that an item or service is expected to be denied by Medicare as not reasonable and necessary, and no Advance Beneficiary Notice (ABN) was provided to the patient. When a provider appends the GZ modifier to a claim, it signals that they believe the service will not be covered, but they did not obtain the patient’s consent for possible financial responsibility through an ABN. As a result, Medicare will automatically deny the claim, and the provider typically cannot bill the patient for the cost. This modifier is primarily used for documentation and compliance purposes, helping healthcare organizations avoid accusations of improper billing.