This study examines dynamics in poverty and food insufficiency using newly available longitudinal data from the 1993 panel of the Survey of Income and Program Participation (SIPP) and the follow-on Survey of Program Dynamics (SPD). The study uses these data to characterize the incidence and dynamics of poverty and food problems for the entire U.S. population and for different subgroups. It also estimates multivariate, discrete-choice regression models to examine the factors associated with transitions into and out of poverty and food insufficiency, and it analyzes the empirical results in the context of a life-cycle model of income and food consumption. Results indicate that the incidence of food insufficiency in the United States is low-less than 3 percent in 1997. There also appears to be little persistence in food problems; 79 percent of people in households with food problems at the start of the study period were in households without problems 2 years later. The multivariate results indicate that female-headed households face an especially high risk of being food insufficient. Low levels of asset income, an indicator of a household’s ability to spread consumption over time, are also associated with food sufficiency problems.