Although Social Security does not currently guarantee low-wage workers a minimum retirement benefit, several proposed reforms include benefit minimums. Our analysis suggests that such policies could help reduce poverty among older adults. However, the way the minimums are designed could affect the extent to which poverty rates decline. Using the Urban Institute's dynamic microsimulation model, we examine five alternative benefit options. Several lessons emerge from these simulations that could help guide designers of Social Security proposals. Understanding how a well-designed minimum benefit could reduce poverty is especially important now, when the program's long-term fiscal deficit threatens future benefit reductions.