Lyman Hall High School is a member of the New England Association of Schools and Colleges (NEASC.) Founded in 1885, NEASC is the nation's oldest regional accrediting association. NEASC's role is exclusively educational. It serves the public and the educational community by establishing rigorous standards of educational excellence and utilizing evaluation processes that focus on self improvement through regular review by educators throughout New England.
Lyman Hall is very proud of its affiliation with NEASC and is committed to maintain its accreditation through focused efforts at school improvement. These efforts include adherence to the school's Statement of Core Values and Beliefs which states,
At Lyman Hall High School, students enter a diverse community that encourages academic growth and challenges them to develop the personal integrity and creative thinking skills necessary for success in the 21st century.