This paper explores how mandated literacy assessment is reorganising teachers' work in the context of Australia's National Assessment Program--Literacy and Numeracy, which was implemented in 2008. Students in Years 3, 5, 7 and 9 are tested annually, with school results publicly available. The wider policy context and the emergence of different forms of interconnected educational work associated with the testing phenomenon are described. Taking an institutional ethnography approach, the local effects of the federal policy regime are examined through a case study of one school. What mandated literacy assessment "does" to educators' work in a culturally diverse low-socioeconomic school community is discussed. Key themes include strategic exclusions of students from the testing process, appropriations and adaptations of literacy theory, work intensification and ethical mediation of results. Questions concerning equity are raised about the differential effects of policy in different school contexts. (Contains 13 notes.)