105 ILCS 5/10-22.33B
To conduct a high quality summer school program for those resident students identified by the school district as being academically at risk in such critical subject areas as language arts (reading and writing) and mathematics who will be entering any of the school district's grades for the next school term and to require attendance at such program by such students who have not been identified as a person with a disability under Article 14, but who meet criteria established under this Section. Summer school programs established under this Section shall be designed to raise the level of achievement and improve opportunities for success in subsequent grade levels of those students required to attend. The parent or guardian of any student required to attend summer school shall be given written notice from the school district requiring attendance not later than the close of the school term which immediately precedes the required summer school program.
105 ILCS 5/10-22.33B