The study examines the selective adoption of the school-autonomy-with-accountability (SAWA) reform at upper secondary school level in Iceland. It draws on a review of policy documents (acts, amendments to acts, regulations) and interviews with 17 individuals, including four former ministers of education that served over the period 1995-2017. The authors identify three distinct reform waves: a general public management reform (NPM) implemented across all sectors (1991-1995), the school autonomy reform (1995-2009), and the school-autonomy-with-soft-accountability reform (2009-2015). The sequence explains why opening up to the private sector during NPM required all line ministries to come up with clearly defined tasks and expected outcomes and why the third wave was an attempt to (minimally) reregulate the sector. The proliferation of standardized testing, a feature of SAWA in many other countries, did not occur in Iceland. Strikingly, the argument for autonomy was from the onset linked to diversity, that is, enabling upper secondary schools to respond to students' diverse needs and interests and thereby reduce student drop. The study attempts to demonstrate the importance of the temporal dimension of policy transfer such as, for example, the timing, tempo, sequence and duration of adopted policies.