We use the Philadelphia Survey of Child Care and Work to model the effect of child-care subsidies and other ecological demands and resources on the work hour, shift, and overtime problems of 191 low-income urban mothers. Comparing subsidy applicants who do and do not receive cash payments for child care, we find that mothers who receive subsidies are 21% less likely to experience at least one work hour-related problem on the job. Our results suggest that child-care subsidies do more than allow women to enter the labor force. Subsidies help make it easier for mothers in low-wage labor both to comply with employer demands for additional work hours and to earn the needed wages that accompany them.