This investigation focuses on the association between modernization and the level and type of membership extension beyond the nuclear core in Philippine families. The data are drawn from the 1970 Philippine Census of Population and the analytical units are the 67 politically defined Philippine provinces. Path analysis techniques are employed. The exogenous variable is a summated t-score of four modernization variables. The endogenous variables are the average size of nonnuclear membership and four components of nonnuclear family membership, including spouse of child of head, grandchild of head, parent of head and other relatives. Modernization is positively associated with overall nonnuclear membership size but is differentially related to the components. Moreover, the nonnuclear membership components have a differential impact on nonnuclear membership size and are differentially associated with each other. Finally, the effects of modernization on nonnuclear membership size are differentially transmitted across the respective components.