Many low-income working families today live one health crisis or job setback away from catastrophe. Some barely make ends meet despite "playing by the rules." Children in these families often lag behind children in better-off families on a range of measures. Over 9 million working families with children lead this precarious existence. Yet, we know little about their dynamics, such as how many families spiral into poverty on the heels of a single crisis. We're just now starting to see strategies that might bolster economic stability. Only careful study rooted in family needs, the workplace, and public programs can germinate bigger ideas.