A wide range of after-school programs have become available to students in grades K-12 over the past 15 years. Programs are generally grouped within those meeting needs related to academic performance (such as improved school attendance, grades, and achievement scores), social/emotional development, and prevention/behavioral outcomes. High quality studies have identified key components of the most effective after-school programs. Programs best support effective outcomes when they are directed by a clear vision, yet flexible to the changing needs of participants; managed by high quality staff who maintain an adult to student ratio between 1:10 and 1:16, and operate for a sufficient length of time (at least 45 hours). Active and consistent student participation in the program is also necessary to reap the full benefits. Additionally, partnerships with schools, families, and the community strengthen after-school programs. Depending on the type of program and how costs are measured, the annual cost can range between $450 and $7,000 per child.