This paper reports on a qualitative study which investigated teachers' explanations for changes to their practice over time. In this study, semi-structured interviews were conducted with 12 teachers from two states in the Northeastern United States of America, asking them to reflect on changes to their practice. These teachers were mostly dissatisfied with the ways their teaching had changed. Teachers' explanations for these changes focused on the constraints they experienced, including district-imposed standards, increased workload and increases in surveillance, all of which they perceived as hindering their development as teachers. This study adds to the body of empirical research seeking to understand changes in classroom teaching practices, particularly in the current era of neoliberal reform.