The Keystone School has developed partnerships with more than 5,000 middle schools, high schools and other institutions to deliver supplemental online and correspondence courses and to create custom, blended learning programs. We offer more than 200 high school and middle school courses, including core, Advanced Placement (AP), world languages, and numerous electives. We also offer more than 40 credit recovery courses that are available for year-round enrollment and also serve as a summer school alternative for many of our school partners. To learn about how Keystone can be your partner in education, call us at 1-800-255-4937 or visit