Charter schools are public schools governed by an independent board of directors that come into existence through a contract with an authorized public chartering agency. This report, known as the Illinois Charter School Biennial Report, provides law and policymakers, educators, and the general public with information regarding the state of Illinois' charter schools. In compliance with Section 27A-12 of the Charter Schools Law [105 ILCS 5/27A-12], it contains information that: (1) compares the academic performance of charter school students to the performance of their peers in traditional public schools; (2) analyzes whether or not exemption from certain regulations allows charter schools to better meet their stated goals and objectives; and (3) recommends any changes to the Charter School Law. This report also includes authorizer-specific information for each authorizer in the state, including: (1) the authorizer's strategic vision for chartering and progress toward achieving that vision; (2) the status of each authorizer's charter school portfolio; and (3) the authorizing functions provided by the authorizer to the charter schools under its purview, including its operating costs and expenses. [For the 2015-16 and 2016-17 report, see ED618450.]