Poverty has been a subject of concern since the beginnings of social work. Three fundamental areas are of importance in understanding the nature of poverty in the United States. First, the extent and dynamics of poverty are examined, including the measurement of poverty, patterns of cross-sectional and comparative poverty rates, the longitudinal dynamics of poverty, and poverty as a life-course risk. Second, reasons for poverty are discussed. These are divided into individual- versus structural-level explanations. The concept of structural vulnerability is offered as a way of bridging key individual and structural determinants to better understand the existence of poverty. Finally, strategies and solutions to poverty are briefly reviewed.