In this chapter, we identify structural features of families with shared physical custody that differ from those of nuclear families or those of families where one parent has sole physical custody, and discuss the implications for family and kin relationships. We pay particular attention to the ways in which shared physical custody alters the gendered nature of parenting and kinship. We argue that the structural features of shared physical custody create distinct contexts for parent-child and sibling relationships and produce differences in shared understandings of obligations between family members. The unique context for relationships and obligations together constitute a new family form. Our analysis generates an agenda for future research on the nature and consequences of shared physical custody.