This executive summary describes a paper that is part of a series intended to encourage the nation's secondary and postsecondary systems to take joint responsibility for substantially increasing the number of young people who are prepared for college and career success. In this report, author Elisabeth Barnett of the Community College Research Center identifies key ways that high schools and higher education can collaborate to redesign the transition from 12th grade through the first year of college and build critical momentum toward completion. Barnett proposes a student momentum framework of specific college preparatory experiences and markers of educational attainment in high school. Students who accumulate these evidence-based "momentum points" are more likely to enter college, avoid remediation, and graduate with a credential of value within a reasonable amount of time. Ideally, secondary and postsecondary institutions would co-design, co-deliver, and co-validate these strategies. The paper focuses on the high school senior year and many of the actions proposed would be delivered primarily by high schools, or by high schools and colleges separately. However, the plans would be created collaboratively--co-designed by secondary and postsecondary institutions, and both sectors would evaluate and co-validate the results. Drawing on the work of other scholars, the paper focuses on three dimensions of college readiness that are rooted in research: (1) Academic knowledge and skills; (2) Noncognitive skills; and (3) College cultural capital. [For the full report, see ED564836.]