BACKGROUND: The objective of this study was to explore associations between maternal depression and anxiety during early sensitive periods, child social-emotional and behavioral problems and the moderating roles of financial, instrumental, and partner emotional support. METHODS: Analyses was conducted using data from the Fragile Families and Child Wellbeing Study. Hierarchical linear regression modeling was used to explore associations between maternal depression and anxiety at 1- and 3-years postpartum, three unique types of social support, and childhood behavioral problems at 5-years of age (n = 2,827). RESULTS: Mothers who were depressed at one or both timepoints, compared to nondepressed mothers, reported higher externalizing behavioral problems scores of 1.96 and 2.90, and internalizing behavioral problems scores of 1.16 and 2.20, respectively, at 5-years of age (both p < .01), after controlling for covariates. Financial, instrumental, and partner emotional support were independently and inversely associated with behavioral problems (p < .05); however, none of these types of support moderated the relationship between maternal depression and behavioral problems, after controlling for covariates. IMPLICATIONS: Promoting maternal mental health as well as different sources of support throughout the first five years of life, instead of one critical period, may help to reduce the burden of chronic disease in the next generation.