Directive (EU) 2015/2193 is transposed into national law by the 44th BImSchV. The ordinance replaces the previously applicable regulations of the TA Luft for combustion plants, gas turbines and internal combustion engine plants in the power range from 1 to 50 MW FWL. In addition to stricter emission limits and shorter measurement intervals, it also contains new verification, documentation and reporting obligations. The operator of a new or existing installation should first contact the competent authority in order not to miss the deadlines and requirements of the 44th BImSchV. For technical solutions, it is advisable to rely on a competent partner with experience who can meet the specific requirements with the necessary technical systems. Anyone operating an existing plant must retrofit continuous emission monitoring for nitrogen oxides (NOx) and prove effective operation of the exhaust gas aftertreatment system. In the case of new plant planning or a significant modification of the engine plant, SCR exhaust gas aftertreatment with integrated emission monitoring must be considered in order to safely comply with the low nitrogen oxide limits.