Genetic and environmental factors account for variability in a range of developmental outcomes, including socioeconomic status (SES). The challenge is to find ways to incorporate genetic information based on studies using biologically related family members (i.e., studies not involving twins). To address this issue, we computed polygenic scores associated with educational attainment (Lee et al., 2018) for the Family Transitions Project (e.g., R. D. Conger & Conger, 2002) and incorporated them into the model tested by R. D. Conger, Martin, and Masarik, (2021). Polygenic scores correlated with observed educational attainment for all relevant members of the Family Transitions Project. Moreover, polygenic scores were correlated with many of the other constructs in the R. D. Conger et al. (2021) model, pointing to the relevance of genetic factors for process models of SES attainment. At the same time, the primary pathways described by R. D. Conger et al. (2021) remained viable when polygenic scores were included in the analyses, suggesting that the environmental pathways predicted by the interactionist model (e.g., R. D. Conger, Conger, & Martin, 2010) are still tenable. The current study thereby illustrates how genetic information can be included in tests of developmental models to clarify SES attainment across generations.