Precarious work – work that is uncertain, unstable, and insecure – has the potential to be quite stressful. This kind of work can disrupt lives, undermine relationships, and erode health. In my dissertation, I examine how working in precarious jobs shapes health and marriage in midlife using longitudinal data from the Health and Retirement Survey. I find that precarious work is associated with the onset of disability and pain that is severe and/or functionally limiting for midlife adults. I also find that the increasing prevalence of disability among midlife adults reflects changes in social factors associated with increases in functional problems, such as increases in precarious work and unemployment during the 21st century. These unfavorable trends outweighed improvements in education and reductions in smoking over this period. I further consider the possibility that differences in exposure to precarious work by race/ethnicity and gender may contribute to population health disparities. Moreover, younger birth cohorts have both greater exposure and greater vulnerability to precarious work, suggesting that the changing nature of work may be undermining health for future generations. Finally, I find that several specific and linked characteristics of precarious work are associated with a greater risk of poor marital quality and divorce for mid- and later-life adults. These results point to the importance of identifying workers at risk of insecure and unstable employment and reducing the adverse consequences of this type of work. This is especially important in light of the persistence and increase in precarious work, poor health, and divorce among midlife adults