We study racial-ethnic disparities in marital and economic status by linking American Community Survey respondents born in 1978-87 to their parents’ tax records. Conditional on childhood family income (CFI), we find that the average Black non-Hispanic woman obtains 60 percent less partner income than does the average White non-Hispanic woman, driven both by a lower propensity to be partnered and a lower partner CFI rank. These marriage market dynamics account for 85 percent of the observed—and large—gap in intergenerational family income mobility. We also show that mobility gaps are larger, and rates of intermarriage lower, in birth areas with greater CFI inequality and racial-ethnic segregation. We discuss a simple model in which these patterns originate from segmentation of the marriage market along racial-ethnic lines combined with imperfect assortative matching on economic status. We comment on the implications of our findings for policy.