The future of the American economy increasingly depends on more students graduating from high school ready for college and a career. Long-standing trends in the nation's dropout rate and achievement gap demonstrate that the American education system needs to better prepare students to meet postsecondary and career demands. While momentum is building to expand learning time for students to help meet these challenges, most efforts have been focused on elementary and middle school students. This brief will explore how expanding the learning opportunities of high school students--to provide flexibility regarding time, location, and delivery methods as well as opportunities to apply knowledge in real-world situations and access social and academic supports--can be used to change the projected skill and knowledge shortages in the nation's workforce. (Contains 28 endnotes.)