Recent efforts to promote marriage among the socioeconomically disadvantaged are based on the assumption that marriage is equally beneficial for persons with varying levels of socioeconomic status. Using 3 waves of data from a sample of married adults (the National Survey of Families and Households; N = 1,849), the authors evaluated whether the health benefits of marital happiness and the health costs of marital conflict might vary by education and income levels. They found that increases in marital happiness were associated with increases in self-rated health for individuals with more education. In addition, increases in marital conflict were linked to greater increases in functional impairment for persons with lower income. Although the results were not consistent and effect sizes were modest, the evidence nonetheless tentatively suggests that higher levels of marital happiness may be less beneficial for health and that higher levels of marital conflict may be more detrimental to health among persons with lower socioeconomic status.