The Ontario Cultural Society of the Deaf became part of Tri-O on March 10, 2018. Tri-O is a one-stop shop for membership to three Deaf organizations in Ontario, which includes the Ontario Association of the Deaf (OAD) and the Ontario Deaf Sports Association (OSDA). Anyone is welcome to become a member on an annual basis and will receive regular communications across all three organizations from one centralized hub. Membership fees paid via Tri-O are shared equally across all three charities.