The absolute size of the foreign-born U.S. population is at a historical high, but neither the share of the population that is foreign born nor the share of children in immigrant families is high compared with the beginning of the 20th century. While poverty rates for immigrants and children in immigrant families are substantial, poverty is concentrated among certain groups, particularly Hispanics and blacks, non-citizens, and recent arrivals. The general economic well-being of immigrants improves with the move to the United States and as time in the United States increases. However, immigrants remain disadvantaged in terms of health insurance coverage. The economic situation of children in immigrant families has declined since the late 1960s, despite the high labor force participation of immigrant men and the lower prevalence of single-parent households among immigrant families. Still, children in immigrant families are at least as healthy as children in native families and are less likely to engage in risky behaviors. With socioeconomic factors taken into account, children in immigrant families do as well as other children in school. Analyses of the socioeconomic well-being of immigrants have been hampered by lack of information in major data sets about legal status and about the visa status of legally present immigrants, as well as by limited availability of longitudinal data.