The Federation of Clinical Immunology Societies (FOCIS) exists to improve human health through immunology by fostering interdisciplinary approaches to both understand and treat immune-based diseases. Initially established as a cross-disciplinary meeting, FOCIS held its first Annual Meeting in 2001. After two successful consecutive meetings, FOCIS incorporated in 2003 as a 501(c)3 organization. Now in its sixteenth year of existence, FOCIS has 57 Member Societies, representing roughly 65,000 clinician scientists. A Federation of this size provides a voice for clinical immunologists and ultimately strives to improve patient care.