In the Supplemental Nutrition Assistance Program (SNAP, formerly food stamps), churn occurs when recipients exit the program and then reenter within four months. Analysis for fiscal year 2011 in six states finds that churning cases comprised 17 to 28 percent of cases ever receiving benefits that year. Most churn occurs at a clients scheduled recertification or interim report, caused by procedural difficulties or changes in household income or other circumstances. Estimates are provided of the benefits forgone among households seemingly eligible while off the program and of the added administrative costs associated with case closings and reopenings.