Objectives. Agency-based support, defined as material assistance received from charities and private social service agencies, can constitute an important source of help for low-income families. This study examines the socioeconomic determinants of agency-based support and seeks to reveal whether it constitutes an alternative source of support for families whose personal networks can provide only limited assistance. Methods. Multivariate analyses were conducted using data from "Welfare, Children, and Families: A Three City Study," a study of low-income mothers living in disadvantaged urban neighborhoods. Results. Findings reveal that respondents with high levels of network support were significantly less likely to use agency-based support. No association, however, was found with network burden, which led to rejecting the alternative hypothesis that people may use agency-based support to limit their interactions with demanding network members. Conclusions. Overall, findings suggest that agency-based support constitutes an alternative source of assistance for those who receive little or no support from family and friends. Policy implications in light of welfare reform are discussed.