The organization of work in the United States has changed dramatically over the last four decades as a result of globalization, industrial shifts, and technological innovation (Burgard et al., 2009; Seigrist & Marmot, 2005; Sverke & Hellgren, 2002). Long-term, stable employment relationships have increasingly been replaced with work arrangements characterized by shorter job tenure and fewer worker protections, leading to an increase in perceived job insecurity (Standing, 2011). Perceived job insecurity is defined as an anticipatory stressor related to the threat of losing a job, or important features of a job, and a sense of powerlessness to overcome this threat (Greenhalgh & Rosenblatt, 2010; De Witte, 2005). The Employment Conditions Knowledge Network of the World Health Organization (WHO) Commission on Social Determinants of Health (Benach et al., 2007) suggests that the effects of perceived job insecurity on health may be even more harmful than job loss itself. Although evidence for a causal relationship between perceived job insecurity and health is growing, little is known about mechanisms and group differences in this relationship. This dissertation investigates the relationship between perceived job insecurity and quality of life. Quality of life is defined in this study as a general state of health, well-being, and satisfaction across multiple dimensions of life (Drotar, 2014; Kobau et al., 2010; Bowling, 1991). Although the WHO defines health very broadly as a "complete state of physical, mental, and social well-being," health is usually assessed in studies of perceived job insecurity in very narrow terms based on the presence or absence of disease (CDC, 2011). In contrast to this deficit perspective on health, quality of life is an overall state of wellness. This dissertation makes an important contribution to the literature on perceived job insecurity and quality of life by achieving three aims: 1) identifying determinants of perceived job insecurity among adults in the United States; 2) testing causal pathways linking perceived job insecurity and perceived inequality at work to quality of life; and 3) estimating group differences in the effect of perceived job insecurity and perceived inequality at work on quality of life based on social status, social resources, and demographic characteristics. Data for this research were drawn from a U.S. sample of non-institutionalized, English-speaking adults in the 1995-1996 and 2004-2006 waves of the National Survey of Midlife Development in the United States (MIDUS). Multivariate generalized ordinal structural equation modeling was used to test hypotheses for the first aim (N=5,424). Multivariate linear structural equation modeling with full information maximum likelihood estimation was used to test hypotheses for the second and third aims (N=5,113). This study was informed by Pearlin and colleagues' (1981) stress process model, which posits that unequal exposure to stressors and access to resources for coping with stressors contributes to health disparities. Key findings from this study add to existing knowledge on job stressors and health. First, for determinants, perceived job insecurity is influenced by objective job insecurity over and above the effects of psychosocial job stressors and demographic characteristics. Effort-reward imbalance also significantly increases perceived job insecurity, but job strain does not. High effort may improve security, but not in the absence of control. People of color report significantly higher perceived job insecurity than non-Hispanic white people, but there is no association between gender and perceived job insecurity, all other factors held constant. Perceived inequality at work is a strong determinant of perceived job insecurity. Second, for consequences, perceived job insecurity is associated with quality of life net of controls for demographic and health characteristics, but not when controlling for other job stressors. Perceived inequality at work confounds the relationship between perceived job insecurity and quality of life. Negative work to family spillover of stress and social support outside of work from family, friends, and spouse/partner significantly mediate the relationship between perceived inequality at work and quality of life. Third, for conditioning factors, the effect of perceived inequality at work on quality of life is conditional on household income, social support at work, age, and wave of interview. No significant group differences were found by education, gender, or race. The findings demonstrate that perceived job insecurity is associated with other psychosocial stressors from established job stress models but that inequality may be even more threatening to health and well-being than insecurity. Stress proliferation from work to family life partially explains the relationship between perceived inequality at work and quality of life. Programs to enhance social support at work and home may help to contain the negative health effects of inequality and insecurity on quality of life.