The number of participants in the Supplemental Security Income program (SSI) and the Supplemental Nutrition Assistance Program (SNAP) skyrocketed during the Great Recession.  But more surprising is that caseloads for both programs increased during the preceding expansion and during the nascent recovery period after the Great Recession.  Using both administrative program data and the Survey of Income and Program Participation (SIPP), this project investigates the persistent growth in SSI and SNAP since 2000 by decomposing each program’s caseload into changes in eligibility, take-up and exit rates, and participants’ duration to determine which of these is responsible for higher caseloads.  While the existing literature on program caseloads in the post-welfare reform era generally excludes the elderly from the analysis, this project is the first to test for differences in elderly and non-elderly caseloads, allowing for different explanations for each: welfare reform, stagnant working-class incomes, and increasing welfare experience among the non-elderly, and medical cost growth and cohort effects among the elderly.  The findings will help policymakers plan for future recessions and better estimate how long individuals will need public assistance.