This article presents a collaborative project, the ‘Austrian Transition to Open Access’ (AT2OA), initially running from 2017 to 2020, which had the overarching goal of enabling the large-scale transformation of publishing outputs from closed to open access (OA) in Austria. The initiative, which has recently secured funding for a second four-year cycle from the Austrian Federal Ministry of Education, Science and Research, brings together all key players: universities, research institutes, the national library consortium and a cOAlition S funding member, the Austrian Science Fund. The project outcomes include a transition feasibility study that builds on the methodology of the 2015 Schimmer et al. article, the seeds of a national OA monitoring data hub and transformative agreements with major publishers. In addition, the project helped launch institutional OA Publishing Funds across the country and explored alternative publishing models. Furthermore, it saw the emergence of a nationwide network of OA experts. The authors also share their thoughts on lessons learned.