The American Group Psychotherapy Association is the foremost professional association dedicated to the field of group psychotherapy, operating through a tri-partite structure: AGPA, a professional and educational organization; the Group Psychotherapy Foundation, its philanthropic arm; and the National Registry of Certified Group Psychotherapists, a standard setting and certifying body. This multidisciplinary association has over 3,000 members, including psychiatrists, psychologists, social workers, nurses, clinical mental health counselors, marriage and family therapists, pastoral counselors and creative arts therapists, many of whom have been recognized as specialists through the Certified Group Psychotherapist credential. The association has 31 local and regional societies located across the country. Its members are experienced mental health professionals who lead psychotherapy groups and various non-clinical groups. Many are organizational specialists who work with businesses, not-for-profit organizations, communities and other "natural" groups to help them improve their functioning.