The series of white papers reported here provide recommendations for research, advocacy, and supports relating to siblings of persons with developmental disabilities. They emanate from the first national meeting of the Sibling Leadership Network (SLN), whose goal is to provide opportunities for the siblings of more than six million Americans with developmental disabilities to increase their involvement in disability advocacy, policy-making and services concerning their siblings with disabilities.  Its mission is “to provide siblings of individuals with disabilities the information, support, and tools to advocate with their brothers and sisters and to promote the issues important to them and their entire families.” The SLN promotes a broad network of siblings who share the experience of disability and people concerned with sibling issues by connecting them to social, emotional, governmental, and provisional supports across the lifespan enabling them to be effective advocates with their brother and sister, and to serve as change agents for themselves and their families.