- Established in 2013, Montessori Alliance of TN is a not for profit registered as a 501 (c)3. We are governed by a Board of Directors composed of Montessori administrators, teachers, and parents. Our Executive Director is Jaime Yeager, co-founder of MAT. MAT began as a conversation and a dream between two Middle TN Montessorians and is now an active state body active in advocacy, consumer protection, and continuing education. MAT is organized by Committees which engage in the work needed to fulfill our mission. Join now!