This research brief explores the effects of marital quality on health. It begins by citing research that getting married and being married is linked to many positive physical and mental health outcomes. Reasons for the link between marriage and good health are then explored, including the “”selection effect”” that occurs when people who are inherently healthier mentally and physically are more likely get married and to stay married; the “”protection”” effect that asserts that marriage itself changes individual health risk behaviors and encourages behaviors that are more likely to promote and protect health; the social support, companionship, caring, and care giving that marriage generally brings to individual partners; and the additional economic resources that are associated with marriage. The links between marital quality and health are then discussed and key findings from both representative population surveys and clinical studies are shared. Findings are organized from a life course perspective and demonstrate the links between marriage and health, highlighting those that focus on marital/relationship quality by stages of the life cycle. Differences in marital effects by gender, race, and income are also considered, as well as the risks of ending a marriage. The final section describes pathways to health in marriages. The brief concludes that the research suggests that a good-enough, or healthy marriage – one that is low in negativity – will provide cumulative, lifelong protection against chronic illness and premature death for both men and women, as well as greatly increasing the chances that their children will grow up healthy. Numerous references.