All ambulances shall conform to the minimum standards of one of the classes set out in 105 CMR 170.455, 170.460, 170.465 and 170.470, and shall be certified accordingly as provided in 105 CMR 170.415 and 170.420. There are three classes of ground ambulances (Class I, II and V), and one class of air ambulance (Class IV).
105 CMR, § 170.450