Some research argues that the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA) substantially reduced college enrollment among targeted poor, single mothers, but empirical evidence is limited on the law’s negative effects. Applying a difference-in-difference-in-difference method to data from the October Supplements to the Current Population Survey for the years 1990–2008, this study finds that PRWORA’s estimated effects on single mothers’ college enrollment vary by enrollment status (full- or part-time) and by the type of institution (2- or 4-year college). Although PRWORA is associated with statistically significant decreases in full-time enrollment in 2- and 4-year colleges between the start of PRWORA and 2002, it also is associated with slight increases in part-time enrollment in both 2- and 4-year colleges between 2003 and 2008. The findings of this study shed important light on issues that deserve attention in the reauthorization of PRWORA.