To address conceptual and methodological shortcomings in the extant literature on student mobility, this study employs event history modeling to describe and explain how state policy levers, specifically state grant aid, relates to mobility and baccalaureate degree completion. We find that state grant aid reduces mobility, but less so than institutional grant aid. We also find that regardless of the form of mobility, it was negatively related to degree completion. This inquiry contributes to work on student mobility, (e.g., McCormick, Transfer behavior among beginning postsecondary students: 1989-94, National Center for Education Statistics, Washington, 1997; Goldrick-Rab, Sociol Educ 79(1):61-79, 2006); extends the long line of persistence research (e.g., Bean, Res High Educ 12(2):155-187, 1980; Pascarella and Terenzini, J High Educ 51(1):60-75, 1980; Tinto, Rev Educ Res 45(1):89-125, 1975) by conceptualizing persistence as student flow within and between institutions; and offers a conceptual tool for policy makers seeking to improve college completion.