The goal of this Keystone meeting “Aging: Immune Function and Organ Health” is to discuss the role of the immune system in organ health during aging. The immune system is emerging as a crucial player in aging. This Keystone meeting will be unique in integrating the latest discoveries in immune function and organ biology, and discuss their importance in aging, longevity, and ‘rejuvenation’ strategies. Exciting recent studies have revealed how aging can be regulated by changes in immune function and inflammation, offering new therapeutic strategies to counter aging and age-related diseases. A key question that this Keystone meeting will be addressing is the impact of the immune system on organ preservation and organ-organ communication, which are critical for organismal longevity. This meeting will also discuss new avenues for therapeutic strategies – based on the immune system – to impact human health. The immunity field is rapidly expanding, and the aging field will highly benefit from being exposed to the latest discoveries in this area, thereby fostering new ideas and collaborations. As a joint meeting with the Keystone Innate Immunity meeting, this Keystone Aging meeting will address innovative questions about the role of the immune system in aging, and how it relates to organ function, and discuss implications and translation for organismal health and disease.