Self-help organizations facilitate mutual assistance in helping communities. They offer a vehicle for people with a common problem to gain support and recognition, obtain information on, advocate on behalf of, address issues associated with, and take control of the circumstances that bring about, perpetuate, and provide solutions to their shared concern. Self-help organizations may be small informal groups, confined to interactive support for their members, commonly called self-help groups, or differentiated and structured multiservice agencies, mutual assistance organizations referred to as self-help agencies. Such agencies are generally directed and staffed by “self-helpers” and distinct from professionally-led organizations. In these agencies, self-helpers are well-represented as board members with the right to hire and fire professionals in the organization Self-help groups and agencies empower members through shared example and modeled success. Of late, community-based professionally-led organizations have attempted to integrate self-help principles into their support service offerings, reflecting ongoing financial and ideological dynamics in systems of care. This effort has led to the development of peer professional helpers, known as peer support specialists, whose contribution to the helping professions are defined by their lived experience. Spread throughout the world, self-help groups, agencies and integrated peer support specialists are considered a major community resource for enabling people to help themselves. This chapter looks at the development, the content, and the effectiveness of self-help organizations and peer support specialists within professionally-led community-based systems of care.