This dissertation consists of three papers that examine the association between family living arrangements and internalizing and externalizing behavioral problems in children. With increasing immigration and growing heterogeneity in family forms, extended family members are of increasing importance in children’s lives. However, knowledge about extended family living arrangements is lacking. The first paper examines the association between the presence of co-resident extended kin and children’s internalizing and externalizing behaviors. Children in the sample were found to be disadvantaged in extended households, especially with regard to internalizing behaviors. This association was found mostly among married-parent extended households. Further, this pattern emerged more clearly among children of documented immigrants, compared to those with native-born parents and those whose parents were undocumented immigrants. These findings suggest a need to revisit previous theories on extended family living arrangements. The second paper examines what kinds of household extension are associated with child behavioral problems. I specify the types of household extension by their relation to the householder—vertical, horizontal, and non-kin. Results from the cross-sectional sample indicate that horizontal extension is associated with higher internalizing behavior problems in children. However, the results from fixed effects models suggest that this pattern may be due to selection effects. Fixed effects estimations show that children moving into vertically extended household increase externalizing behaviors or that children moving out of a vertically extended household decrease externalizing behaviors. I discuss what implications this type of transition represents. The third paper examines the interaction between extended family household structure and neighborhood characteristics on children’s behavioral functioning. Findings suggest that the co-residence with extended kin is associated with both higher internalizing and externalizing behaviors for children. Although the health disadvantage of living with extended kin seems to be independent of the neighborhood income and racial minority concentration levels, extended kin moderate the associations with neighborhood structure. The advantage of living in higher-income neighborhood strengthens for extended families, reducing internalizing behavioral problems in children. Minority concentrated neighborhood functions as an advantage for extended families, decreasing externalizing behavioral problems. I conclude with discussion of future research and policy implications.