This article examines the relationship between private safety nets and economic outcomes among 2,818 low-income single mothers in three U.S. counties in the 1990s. I define private safety nets as the potential to draw upon family and friends for material or emotional support if needed. Using a combination of survey and administrative records data collected for the National Evaluation of Welfare-to-Work Strategies, I find that human capital deficits, depressive symptoms, and low self-efficacy are associated with having less private safety net support, suggesting that social network disadvantages compound individual-level disadvantages. I also find that mothers with strong private safety nets worked more, earned more, and were less reliant on welfare compared with mothers with more meager private safety nets.