As of 2011, 43 percent of families endured swings of more than 25 percent. Such fluctuations, also called income volatility, make it difficult for families to plan, pay regular expenses, save, or pay down debt. But little research has investigated and compared the impact of changes in year-to-year income on American families, including those of different incomes, races, education levels, and ages. This analysis aims to fill that gap by exploring what, if any, differences exist between families that experienced income volatility and those that did not, as well as between those that had income gains and those that had losses, and by examining the relationship between income volatility and overall family financial security.