In countries around the world, population aging, technological change, and labor market transformations are leading to an increasing incidence of mismatch between the skills and credentials held by workers and those required by their jobs. This is leading large numbers of people to return to schooling to enhance their prospects in the workplace. Access to adult education is highly stratified, and the returns to educational re-entry vary across social categories. This state-of-the-art paper focuses on two aspects. First, it examines the degree to which adult education (specifically, degree-bearing education) most benefits the less advantaged and thus mitigates socioeconomic inequality (second chance effects). Second, it addresses the degree to which the benefits of adult education go primarily to those who are already advantaged (Matthew Effects). Our review adopts the perspective of the socioeconomic life course and is explicitly cross-nationally comparative.