Prisoner reentry remains one of the most critical social problems confronting America, one that brings with it many social and economic costs. The mass incarceration that has occurred in recent decades has resulted in 1.6 million individuals currently in state and federal prisons with approximately 730,000 inmates released annually. More than two thirds will be re-arrested within 3 years of release. The fact that ex-prisoners face challenges upon release, which contribute to these adverse outcomes, creates substantial cause for concern for the well being of these individuals and for the communities to which they return. Policy makers and researchers have responded to the problem through a plethora of new policies and programs and an increasingly large body of research on prisoner re-entry. Successful efforts to promote large-scale improvements in prisoner re-entry require more information about effective programs and policies, but such efforts depend heavily on accurate information about the factors that give rise to the types of successful re-entry experiences that benefit ex-prisoners and, in turn, society.