Charter schools are publicly funded elementary or secondary schools that have been freed from some of the rules, regulations, and statutes that apply to other public schools, in exchange for some type of accountability for producing certain results, which are set forth in each charter school's charter.

The charter school movement in the United States began in 1988, when Albert Shanker, President of the American Federation of Teachers, called for the reform of the public schools by establishing "charter schools". As originally conceived, the ideal model of a charter school as a legally and financially autonomous public school (no tuition, religious affiliation, or selective student admissions) that would operate much like a private business – free from many state laws and district regulations, and accountable more for student outcomes rather than for processes or inputs (such as Carnegie Units and teacher certification requirements). However, opponents of charter schools suggest that this accountability is rarely exercised, and that the more lax requirements for charter schools result in fewer qualified teachers than at their traditional public counterparts.

Minnesota was the first state to pass a charter school law, in 1991. California was second, in 1992. By 1995 there were 19 states with charter school laws.

There are two principles which guide charter schools. First that they will operate as autonomous public schools. This is effected by gaining waivers from many of the procedural requirements of public schools. Second, that they will use innovative pedagogy. To justify their waivers and autonomy, they are supposed to produce results superior to non-charter schools. However, studies have shown that charter schools are rarely closed for poor academic performance.