Research shows that earning college credit while in high school increases students' chances of going to college directly after high school and of earning a college credential. Research also makes clear, however, that access to early postsecondary opportunities is uneven, with lower rates of participation among students of color, those from low-income families, and those from other groups underrepresented among college graduates (e.g., English learners and students with disabilities). Moreover, research indicates that to be effective with students who do not have clear plans for college after high school, solely enabling students to take college courses is not sufficient; students from underrepresented groups also benefit from outreach, advising, and strong teaching and academic support building on their interests to further motivate and guide them to pursue postsecondary education after high school. This brief examines research on the five most common college-credit-in-high-school models and assesses their potential as large-scale on-ramps to postsecondary programs that lead to career-path employment for students who have not been well served historically in the transition from high school to college and careers.