Expanding access to engineering for underrepresented groups has by and large focused on ethnicity/race and gender, with little understanding of socioeconomic disadvantages. In this study, we use economic, human, and cultural capital theories to frame and then describe access to undergraduate engineering degree programs and bachelor's degrees. Using individual student-level data from 10 universities from the Multiple-Institution Database for Investigating Engineering Longitudinal Development (MIDFIELD) and aggregate school-level data (i.e., free-lunch status) from the Common Core of Data between 1994 and 2003, we first describe students who enter engineering programs by peer economic status (PES) with attention to gender, ethnicity/race, and SAT Math score. Second, a subset of the data is analyzed to describe access to bachelor's degrees in engineering by PES using graduation rates. The findings show an increase in access to engineering degree programs by disadvantaged students, but that access to engineering bachelor's degrees may be constrained, and especially for underrepresented ethnic/racial groups. The data highlight variable PES differences that accrue in engineering at entry and upon graduation (6 years later) across ethnic/racial groups; these differences have implications for broadening participation. Recommendations for future research and improving engineering access at the secondary and postsecondary levels are discussed.