The current study utilized a social exchange perspective to examine relations among 74 adolescent mothers' perceptions of barriers to father engagement, parenting alliance strength, and nonresident fathers' engagement in caregiving and nurturing activities with their children. Even after accounting for mothers' perceptions of barrier strength, mothers who viewed the parenting alliance as strong also perceived fathers as more engaged in caregiving activities. A more complex pattern emerged for mothers' perceptions of father engagement in nurturing activities, such that relations between barrier strength and fathers' nurturing depended on the parents' relationship status and parenting alliance strength. Our findings suggest the importance of helping young parents strengthen their coparenting relationship in order to foster fathers' engagement with their children.