• Since 1904, Lyons Township High School District 204 has been a charter member of the North Central Association (NCA), a subsidiary of AdvancEd. AdvancEd is a non-profit, non-partisan organization that conducts rigorous, on-site external reviews of Pre-K-12 schools and school systems to ensure that all learners realize their full potential. LTHS is fully accredited by AdvancED and maintains its accreditation by participating in its Continuous Improvement System based on its Performance Standards.