Higher education institutions are utilizing comprehensive college transition programs (CCTPs) to streamline support, promote retention and success, and address the structural barriers that at-promise students face. Yet, research about the role of CCTPs rarely explores the importance of major and career self-efficacy (MCSE) for these populations, despite the established connection between MCSE and success outcomes. External pressures on degree attainment further emphasize the importance of major and career decision-making processes. Based on longitudinal survey data from the Promoting At-Promise Student Success (PASS) project, quasi-experimental modeling shows that CCTP participants have significantly greater MCSE than students without program exposure, which points to the important role of major and career-related programming and support implemented as part of CCTPs to promote at-promise student success. Implications for advancing the development of MCSE for low-income, first-generation, and racially minoritized students are offered as potential strategies for addressing equity gaps related to retention and completion.