Motherhood is a physiologically and behaviorally demanding process. We sought to examine how such changes might be expected to alter a mother’s social position within her group and whether there were physiological changes concomitant to these dynamics. We collected social behavioral data over two birth and breeding seasons on 120 females across two mixed-sex groups of rhesus macaques (Macaca mulatta) at the California National Primate Research Center. We also collected blood samples (from all available females in the first birth season and N = 60, thereafter) for blood chemistry and cytokine assays. Maternal dynamics exhibited a strong influence on the group’s sociality. We observed increased connectivity and investment for proximity and contact-sit beginning in late pregnancy, continuing after birth, relative to non-mothers. Grooming connectivity and investment increased during pregnancy, compared to non-mothers, but decreased after the first 50 days postpartum. The number of infants in the group increased social associations for all behaviors, except huddling, yet only in the first birth season. Maternal assortment increased, likely due to a higher number of mothers available as social partners; postpartum, however, kin assortativity did not dramatically change. Though reproductive status did predict variation in biomarkers, behavioral patterns did not show any association despite the aforementioned between maternal status and social behavior. In summary, maternal social behavior exhibited marked differences across the phases of pregnancy and postpartum, yet these behavioral changes were not associated with physiological benefits or costs beyond those associated to shifts in maternal status.