The project is part of the Project ROS that is an implementation intervention project of a gatekeeper training program at five FGU schools (one FGU institution) in Denmark. The "Preparatory Basic Education and Training," or "Forberedende Grund Uddannelse" (in Danish), is a state-funded program in Denmark that helps young people (ages 15 to 25) develop their social and personal skills in order to start and continue their secondary school education or find employment. A new study, describes that more than half of the teachers at FGU schools have experienced students that have suicidal behavior. Teachers regularly interact with students, making it appropriate to consider introducing a school-based suicide prevention intervention, like a Gatekeeper training program (GKT). The purpose of GKT is to raise staff members' confidence in their own abilities to intervene (e.g., by giving them the courage to discuss suicide and deal with a suicidal crisis). Implementation research involves the study of the context, implementation outcome variables, factors affecting implementation, and implementation strategies. This project serves two primary objectives. The initial aim is to investigate various factors, encompassing student characteristics, the structure of FGU, and the gatekeeper training programs (GKT) designed for teachers in schools with high-risk youth. The second objective involves the development, planning, and execution of a feasibility study for GKT, guided by a comprehensive examination of contextual factors and an assessment of the intervention's suitability. The Project is constructed upon the framework “Implementation stages”. The implementation stages framework is being explored for practical implications for the ROS intervention. The project is comprised of four interconnected studies. In order to determine which GKT program is most appropriate for FGU schools and what barriers and facilitators exist there, the first three studies will examine these topics. This information will then be used to guide the creation of implementation strategies. The final and fourth study will evaluate the effectiveness of the GKT program and implementation strategies. The project and preliminary results from the first two studies will be presented during the symposium.