Education policies are rarely implemented as they have been written or planned. Instead, school principals interpret and apply these policies according to their professional role identity and sensemaking. This study highlights the importance of the micro-institutional context. Specifically, it addresses the professional role identity and sensemaking of individuals who are responsible for policy translation and implementation. I find that policy implementation depends on the interlaced relations between the principal professional role identity and sensemaking. As such, principals differ in the way they notice, process and react to different policies. These variations in policy adaptation and implementation, resulting in organizational heterogeneity.