While mathematics education research has often focused at the level of the classroom (Rousseau Anderson & Tate, 2008), there are emerging calls for attention to shift from individual classrooms to consider the process of reform at the school or district level. Investigating the role of the institution and conditions of the organization becomes crucial in order to fully understand classroom practice and to move beyond existence proofs to take reform to scale (Cobb & Jackson, 2011; Cobb & Smith, 2008). While the need to design instructional improvement is not limited to a particular school or district type, it is arguably most critical for urban settings. There is an urgent need to develop and test models that can be used for the design of more effective urban schools and districts (Cobb & Smith, 2008; Tate, 2008a). While any model of school or district reform should involve the development of "testable conjectures about the constraints and affordances of the institutional setting" (Cobb et al., 2003, p. 21), the specific conditions of urban schools are crucial to consider. As such, the purpose of this commentary is to offer design considerations that are specific to urban schools. The author's intent is to contribute to theory- and model-building regarding urban mathematics education by outlining how the design process for mathematics reform might be influenced by the geospatial context.