The National Mirror Groups (NMG) are a national reflection of the working groups set up by the 1+MG Initiative. Due to the differences among countries, both in terms of research and innovation and health systems governance and in terms of approaches with respect to the 1+MG initiative, mirror groups are set up in different configurations. Furthermore, some of these member states are still in the process of establishing them. For this reason, it is necessary to map the configurations of the NMGs in the different countries to identify the commonalities on the NMG configurations and if these configurations can be correlated with peculiarities of the different National Health Systems across Europe and with the implementation of the initiative at the national level. This mapping will also help us to know how and to what extent NMGs connect with their national initiatives. To this aim, the following actions have been carried out: The development of an initial factsheet (see section 10.1) called ‘National Mirror Groups at a Glance’ to help countries clarify the mission, role, tasks and structure of NMGs in the initiative for the time being. A survey (see section 10.2) has been circulated among the participating Member States and the Observer Countries of the initiative and was analysed the different existing mirror groups assessing its structure, composition, governance, and operating modes and if they were correlated with their national structures. Bilateral meetings have been held with some countries to gain knowledge about the structure and operation of NMGs in those countries and its implementation at the national level. After analyzing the results, it has been found that in most of the countries (10 of 19)he WG1 representative is the main figure that coordinates the NMGs that only 22.22% of the countries (4 of 18) consider that their NMGs are ‘Operational’, and just over half of the countries consider that there is engagement between their NMGs and the initiative. Besides, the composition of the NMGs is quite heterogeneous among countries. Regarding the representation of stakeholders, it should be noted that most of the countries have a high representation of the research and university communities and not so much of the clinics. To achieve the goals regarding NMGs set up in the roadmap of the initiative, it would be recommendable that at least 75% of the countries have their NMGs operational by the end of 2021, that all NMGs have a high engagement with the initiative and they be aligned with national initiatives and countries feed their NMG with stakeholders related with patient organisations, industry and clinical communities. This data has enabled us to set up some guiding principles and identify a first set of best practices for the good set-up, running and coordination of mirror groups.