Research in the intergenerational transmission of socioeconomic status (SES) consistently shows that the SES of one generation benefits the next. Demographic processes shape the kin structures that serve as conduits for the transmission of SES. Few studies have examined these trends together to describe experiences in evolving kin structures throughout the life course and across generations. This article applies demographic techniques to fertility, marital, and mortality data from three generations in the Panel Survey of Income Dynamics to simulate the amount of time young adults would spend within consequential kin structures. High-SES adults spend more years of their young adulthood in advantageous kin structures with greater potential for kin support and capital accumulation, while low-SES adults spend a larger portion of their young adulthoods as single parents, sandwiched between widowed parents and children, and as adult orphans. The kin network inequities have grown since the 1980s, driven by lagging mortality improvements and increasing single parenthood among low-SES families.