This paper argues for a radical restructuring of education for grades 11-14--by erasing the arbitrary dividing line between high school and college--to open opportunities for the learners the current systems leave behind. The authors make the case for an entirely new type of institution--neither high school nor college--designed specifically to better meet the needs of young people after 10th grade and help prepare them to succeed in the world of work. The authors take a hard look at the obstacles that impede more than half of the nation's young people from making successful transitions from high school to postsecondary education to the labor market despite the best of intentions of the many who support them. They identify the four key areas that need transformation: (1) incentives (in accountability and finance); (2) alignment; (3) governance; and (4) staffing. For each, the authors provide examples of innovation--existing policies, programs, and networks--that have made strides toward smoothing transitions. Last, the authors recommend an action agenda of next steps to start pushing closer to the ideal. [For the executive summary, see ED614770.]