This study investigates how poverty and residential mobility affect adult persistence and participation in family literacy (FL) programs. Combining data from interviews with directors and participants from a sample of FL sites in Pennsylvania, this study examines (a) the perceptions of practitioners and adult learners regarding the role of residential instability in shaping FL program persistence for low-income adults, and (b) how determinants of persistence may vary across urban and rural contexts. We argue that poverty mobility coupled with particular structural features of community is often more salient to program persistence than are features of individual programs and/or participant "motivation." (Contains 2 tables and 3 endnotes.)