A Practice Note addressing the requirements for air ambulance service providers under the No Surprises Act (part of the Consolidated Appropriations Act, 2021 (CAA-21)). This resource reflects interim final regulations (IFRs) (issued in July and October 2021) implementing the No Surprises Act's prohibitions on surprise medical bills and balance billing for air ambulance service providers, including the independent dispute resolution (IDR) process. This Note also includes details on proposed regulations, issued in September 2021, to implement the No Surprises Act's reporting requirements for air ambulance service providers, as well as enforcement and penalty mechanisms.