Over the past decade, Argentina created and implemented a compulsory lower-secondary education level, within an ambitious educational reform programme. This article addresses the reform at the national level, diverse provincial responses, and the particular way that the powerful province of Buenos Aires appropriated the structural change. The authors' main source of data is fieldwork in Argentina, specifically in that province, in May 2002; they gathered official documents, interviewed national and provincial policy-makers, educational researchers and school actors, and observed schools and classrooms. The authors analyse the ways actors form and appropriate educational policy at three levels--national, provincial, and school--and within the limits set by various global, national. and local policy discourses. After reviewing the historical background and context of Argentina's reform, they discuss national education policy during the 1990s, focusing on the change in academic structure, and the different provincial responses and implementation problems. They then analyse the case of the province of Buenos Aires (PBA). Finally, they summarise some quantitative effects of the reform. (Contains 1 table and 3 notes.)