The annual number of living kidney donors in the United States peaked at 6647 in 2004. The preceding decade saw a 120% increase in living kidney donation. However, since 2004, living kidney donation has declined in all but 1 year, resulting in a 13% decline in the annual number of living kidney donors from 2004 to 2011. The proportional decline in living kidney donation has been more pronounced among men, blacks, younger adults, siblings, and parents. In this article, we explore several possible explanations for the decline in living kidney donation, including an increase in medical unsuitability, an aging transplant patient population, financial disincentives, public policies, and shifting practice patterns, among others. We conclude that the decline in living donation is not merely reflective of random variation but one that warrants action by the transplant centers, the broader transplant community, and the state and national governments.