Programs that provide housing assistance, unemployment benefits, health care, and welfare to low-income people and others in the United States have a complex structure. Each program has a different mix of federal, state, and local roles in financing, in determining who is eligible for benefits, and in deciding what those benefits will be. Even if this complexity can be juggled reasonably well for families, individuals, local governments, and states during normal times, however, Hurricane Katrina posed a severe test. This paper explores how these programs fared under the extreme conditions of the storm and its aftermath.