The New York City P-TECH 9-14 schools are an educational model that ties together the secondary, higher education, and workforce systems to improve outcomes across domains. The distinguishing feature of the model is a partnership among a high school, a community college, and one or more employer partners that focuses on preparing students for both college and careers within six years. P-TECH 9-14 schools collaborate with local colleges to provide students with an opportunity to earn a high school diploma within four years, followed by a cost-free, industry-recognized associate's degree. During the six-year program, employer partners provide students with work-based learning experiences such as internships, mentoring, and job shadowing. This evaluation provides the first rigorous evidence about the effects of the P-TECH 9-14 model on student outcomes. The study uses a lottery-based random assignment design that takes advantage of the nature of the New York City high school admissions process, in which students were randomly offered or not offered an opportunity to attend a P-TECH 9-14 school. This study has also investigated how P-TECH 9-14 schools implemented the elements of the model, and where implementation varied among schools, and has conducted a cost and cost-effectiveness analysis, which assesses the impacts relative to the cost of obtaining them. [For the Executive Summary, see ED632481.]