- These are the slides and results from a workshop "Plan S implementation by institutions and libraries" we did at OAI11 – The CERN-UNIGE Workshop on Innovations in Scholarly Communication in Geneva, June 19th, 2019. The workshop description: Plan S aims to accelerate the transition to open access by imposing stricter open access rules on funded researchers. This has an effect on many actors, including institutions and their libraries. They will have to think about if and how to support Plan S, how to achieve transformative agreements, how to advise researchers, and more. This workshop is intended to bring together ideas and opinions on how institutions and libraries could and should relate to Plan S. Using the information available on possible concrete ways for researchers to achieve compliance for their publications (many of which are already exist and are proven in practice), what are the roles and responsibilities for institutions to support them in that? How do we make sure that the goal of Plan S is achieved while ensuring a diverse and sustainable open access landscape? After getting an overview of Plan S and after hearing the participants’ perspectives on Plan S, the group will explore known problems and approaches. We will also look at the points raised in (public) input provided by institutions during the consultation around Plan S, and discuss how the position of institutions is influenced by their national contexts, the disciplines they serve and other factors. Topics to be discussed can range from: considering institutional policies (will institutions decide to implement mandates in line with plan S?) negotiations with publishers towards transformative agreements and also publishing agreements with full OA publishers considering investing in common infrastructure, such as disciplinary repositories and OA publishing platforms developing institutional OA publication platforms making institutional repositories plan S compliant informing and supporting their researchers At the end of the workshop, we will have an overview of possible actions and choices on the topics above, with some criteria that institutions can apply to their Plan S implementation processes. While this workshop focuses on the implications of plan S for institutions (and their libraries), participation is not limited to representatives from institutions/libraries - other actors are welcome to contribute to this discussion from their perspective.