Financial factors such as tuition costs and financial aid have substantial influences on college access. Prior studies have examined how financial factors influence cohort patterns of incoming students. Our study adds to that body of work by studying institutional differences in the effect of college costs and financial aid on access. We particularly focus on engineering students and explore access of an important underrepresented group in engineering—students of low socioeconomic status. We utilize two large databases: the Integrated Postsecondary Education Data System (IPEDS) and the Multiple Institution Database for Investigation of Engineering Longitudinal Development (MIDFIELD). We employ descriptive statistics, nonparametric test, and a difference-in-difference regression model to determine the relationship between financial factors and engineering cohort patterns. We demonstrate the inability of grant aid to match the pace of rising tuition and fees, and identify different trends between institutions with and without merit-based scholarships. The adoption of merit-based scholarship was positively correlated to in-state student enrollment, engineering first-time student enrollment, and the fraction of students with high socioeconomic status. Compared to the overall institutional effect of merit-based scholarships, engineering experienced a larger increase in the fraction of students with high socioeconomic status. The scholarship effect was not consistently related to in-state students’ SAT scores. Variations in significance and direction exist in the results across institutions.