An understudied contributor to the massive growth of American incarceration is an increase in the practice of reimprisoning parolees through parole board revocations—now referred to as “back-end sentencing.” To conduct the analyses outlined in this article, we use data from the California Parole Study to analyze the effects of three clusters of factors (parolees' characteristics, organizational pressures, and community conditions) on these sentences. Our analyses are informed by theories that have been used to explain “front-end” (court) sentences, which center on the focal concerns of social-control agents, labeling, and racial threat. Our results indicate that status characteristics—race/ethnicity and gender—affect the likelihood that criminal parole violators are reimprisoned. Moreover, certain “pivotal categories” of parolees—registered sex offenders and those who have committed “serious” or “violent” offenses—are much more likely to be returned to prison than others. Organizational pressure (prison crowding) also affects the likelihood of reimprisonment. Communities' political punitiveness affects the likelihood that technical violators are reimprisoned and that serious or violent offenders are reimprisoned for criminal violations. In this article, we use these findings to consider ways that mass incarceration is driven by both top-down policies as well as bottom-up organizational and community forces.