This study examines the interaction between Food Stamp Program (FSP) and Temporary Assistance for Needy Families (TANF) program participation, provides a model of joint decisions made by households on FSP, TANF, and labor force participation, and explains why households choose different alternatives. We use the first Survey of Program Dynamics (SPD) longitudinal data and the 1998 SPD experimental data files. The modeling component consists of estimating equations to predict the probability of particular choices made by households. The households choose the alternative that gives the highest utility. The results show that the program parameters do matter. Variations across states in payment standards, benefit reduction rates, and income disregards help to identify household choices.