This article presents findings from multiple years of evaluation of STEM-focused school-university partnerships. In addition to developing the three empirically grounded models of structural partnership configurations for project effectiveness, the CSEP team used these models to examine partnership projects for their characteristic collaborative implementation processes. This essay specifically applies questions that deal with project viability and sustainability--across the full range of Illinois ITQ projects--revealing which collaborative structures and processes make the projects sustainable and which do not. (Contains 1 table.)