The EU Regulation 1143/2014/EC (IAS Regulation) recognizes the need for a coordinated set of actions to prevent, control and mitigate Invasive Alien Species (IAS) in Europe. The IAS Regulation gives priority to a list of species, named as IAS of Union concern. The current report defines an EU baseline of spatial distribution for the 18 species added to the Union list in 2019, based on the assessment of data aggregated through the European Alien Species Information Network (EASIN) in collaboration with the Competent Authorities of 16 EU Member States. The report also provides species traits, which have a key role in biological invasions management. For each IAS, the year and country of first introduction in the EU, the main pathway of introduction, the taxonomic group, the habitat, the origin, and the impact are given. The distribution baseline has revealed that most IAS have been introduced and spread across western EU countries, while their presence is more limited in eastern MS. Several species are already quite widespread across the EU (e.g. Lepomis gibbosus, Ailanthus altissima), other are still rare (e.g. Andropogon virginicus, Arthurdendyus triangulatus) or are completely absent from the EU (Lespedeza cuneata, Lygodium japonicum, Plotosus lineatus, Cortaderia jubata). Most IAS were primarily introduced in the EU through escapes linked with introduction for ornamental purposes, and aquarium trade before the 1950’s. Most of them originate from East Asia. This baseline constitutes an important tool supporting the implementation of the IAS Regulation.