Old versus new: Progress in reaching the goals of the new kidney allocation system

As demand for kidney transplant continues to grow faster than organ availability, appropriate allocation of deceased donor kidneys is an acute priority. Increased longevity matching is central to this effort. To foster equitable and efficient utilization of deceased donor kidneys, a new kidney allocation system (KAS) was introduced in December 2014. Major achievements in the 1 year after its implementation include a reduction in age-mismatch and an increase in access to transplant for historically disadvantaged candidates, such as those with very high levels of panel-reactive antibodies or long dialysis duration. However, the rate of discarded kidneys has not decreased, and an increase in A2/A2B transplants has yet to be realized. Organs are now shared more often at the regional and national levels, with some regions experiencing an increase in transplants and other a decrease. While implementation of the KAS has been associated with the attainment of key goals, the kidney transplant community must remain vigilant about potential untoward consequences, including reductions in transplant rates for specific groups such as pediatric patients. More time is required before firm conclusions about the long-term effects of the new KAS can be rendered.