This booklet focuses on the role of interagency agreements in facilitating the transition of young children and their families from early intervention services to preschool services as children turn 3 years of age. Interagency agreements can be viewed as an "invisible brace" supporting families and staff as they consider many issues in moving from one service system to another. Interagency agreements can expand educational options while reassuring those legally and fiscally responsible for children's educational programs that they are acting properly. The role of service programs and the local interagency council in developing an interagency agreement for transitions is discussed. Laws that underlie the services for young children with disabilities and special needs are reviewed. Issues to be considered in drawing up an interagency agreement include: guidelines to promote continuity of services, avoiding duplication of assessment, logistical and technical support issues, and the level of formality. Two vignettes describe service transitions and the impact of interagency agreements. Components of a good interagency agreement are listed. The booklet closes with an interagency agreement currently in use and a model agreement. (JDD)