Research on the increasing concentration of poverty in the 1980s gave renewed prominence to the role of neighborhood conditions in social policy. This paper begins an examination of trends in this phenomenon during the 1990s, covering all U.S. metropolitan areas. It opens with data on patterns of increase and decrease in concentrated poverty, nationally and for different regions and types of metropolitan areas. Data are presented using both a 40 percent and a 30 percent poverty rate cut-off for defining high-poverty census tracts. The paper also examines the mechanics by which these changes took place. The central finding is that, after decades of moving in the other direction, poverty became notably less concentrated in the 1990s. The share of the metropolitan poor who live in high-poverty neighborhoods (poverty rates of 30 percent or more) increased from 25 to 31 percent in the 1980s but dropped back to 26 percent in 2000. The share of all such neighborhoods in large central cities and predominantly black populations declined while shares of those in the suburbs and those with predominantly Hispanic populations increased.