In the United States, after elementary school, students attend middle school (also known as junior high school) for three years, typically from ages 11 to 14. After middle school, students continue at high school, which lasts for four years, typically from ages 14 to 18. In some states, students have to stay in school until they are 18 years old, while in other states they may leave school at 16 or 17 with parental permission.