Forty-four states have charter schools in operation, the National Alliance for Public Charter Schools says.
For a charter school to open its doors, it must have a sponsor or authorizer that determines how it will be run. The kinds of entities that are allowed to be charter authorizers varies from state to state, but the National Association of Charter School Authorizers identifies six categories:
•Higher education institutions
•Independent charter board
•Local education agency
•Non-educational government entity
•Not-for-profit organization
•State education agency
The Texas Education Agency (TEA), the state's education department, is the charter authorizer that accounted for the most charter school students in 2016-17, according to statistics compiled by the Alliance. The campuses authorized by the TEA accounted for 268,258 students.
These were the Top 10 authorizers in 2016-17:
