Practice sustainability is important to ensure that students have continued access to evidence-based practices. In this study, respondents from a national sample of 860 schools at varying stages of implementing school-wide positive behavioral interventions and supports (SWPBIS) were administered a research-validated measure of factors predicting sustained implementation of school-based practices. School demographic characteristics and specific school team actions were assessed to indicate which variables were most strongly associated with the four sustainability factors. Findings showed that in general, school demographic characteristics were not significantly related to sustainability. School team actions, especially the frequency of sharing data with the whole school staff, were statistically significantly related to sustainability. Implications for enhancing sustainability of school-based practices are discussed. [This paper was published in "Assessment for Effective Intervention" v40 n3 p184-191 2015 (see EJ1058456).]