Like public schools and charter schools, enrollment in nonpublic schools is usually free of charge to the parent. Nonpublic schools, however, are generally viewed by public agencies as placements of last resort so access to them is limited by the public agency with which they contract. In some states, the use of nonpublic schools to serve at-risk students is limited to a specific percentage of the at-risk population regardless of demand. Parents can place their children directly into a nonpublic school assuming the child fits the school’s admission criteria at private expense.