Based largely on interviews with stakeholders in California, New York, Tennessee, and West Virginia, this report describes how these states have established initiatives related to early college readiness assessments and transition curricula. It then compares the development of these interventions across states and identifies factors that have facilitated or hindered their implementation. Findings suggest that strong collaboration between the K-12 and higher education sectors in developing such initiatives is essential for ensuring that the skills and knowledge taught and assessed in high school are well-aligned with those needed for success in college. What is more, program designers need to carefully consider competing priorities concerning initiative goals, populations served, and course content. The study also suggests that state-level commitment to improving college readiness in the form of legislation may be helpful in building support and momentum.