The United States has the highest incarceration rate in the world. After remaining relatively steady for 50 years, the rate of inmates incarcerated under state and federal jurisdiction more than quadrupled in 30 years, from about 200 per 100,000 population in the mid-1970s to about 900 per 100,000 in the mid-2000s. This imprisonment binge has been one of the most dramatic developments in contemporary American society. While research on the nature of crime, prisons, the effects of imprisonment on individuals, and the policies leading to this sharp increase in the incarceration rate have flourished, less is known about the collateral consequences of mass imprisonment on society as a whole. Recent research, however, has begun to address this topic on a broader scale. The scholars on this panel present findings that examine the collateral consequences of mass imprisonment on neighborhoods, social institutions, and social stratification. Using carefully constructed datasets and sophisticated methods, they estimate the sizes of national- and state-level populations of ex-felons since World War II, the impact of incarceration on levels of neighborhood disadvantage, and the effect of mass incarceration on ethnic stratification. The findings from these studies shine a light on the social consequences of mass incarceration and its effect on community characteristics such as social disadvantage and health, and have direct implications for social institutions such as civic engagement.