Conn. Gen. Stat. § 10-265l

(b) Subject to the provisions of this subsection, each local and regional board of education for a priority school district may require, within available appropriations, (1) for the 2005-2006 school year, students in the fourth and sixth grades in schools under its jurisdiction who fail to make progress with the additional instruction provided in their personal reading plans to attend school during the summer following the school year in which the student fails to make such progress, and (2) for the 2006-2007 school year, and each school year thereafter, students in the schools under its jurisdiction who fail in fourth, fifth or sixth grade to make progress with the additional instruction provided in their personal reading plans to attend school the summer following the school year in which they failed to make such progress. The superintendent of schools may exempt an individual student from such requirement, upon the recommendation of the school principal. If a student does not receive such an exemption, has been offered the opportunity to attend a summer school program and fails to attend summer school, the local or regional board of education shall not promote the student to the next grade.