There is a long waiting list to get a kidney transplant in the United States - sources vary, but circle around 90k individuals on the list as of market creation.

If, by 2050, there is still a waiting list to receive a kidney transplant (and there has not at any point between now and then been a moment where the waiting list was exhausted), then this market will resolve as "2050 or Later".  

If the waiting list is exhausted temporarily and then resumes, the market may resolve according to the year it was exhausted as long as the waiting list was eliminated* for at least one year. 

*Note: This market may resolve if there is still a waiting list, but all members of the list expect to receive their transplant without a significant wait (<1 year). Some slack in the system is expected.

The long wait times and challenges associated with receiving a kidney transplant cause significant challenges to those in need. Because a human can live healthily with only one kidney, altruistic individuals can choose to donate a kidney to someone in need. Whether there will be a waitlist in the future is decision-relevant to potential donors, as their decision to donate a kidney may depend on assumptions around when/if there will be alternative solutions such that the kidney transplant waiting list is eliminated in the coming years. 

Potential solutions to this issue range from the development of lab-grown organs, increased organ donation rates, changes in policies that restrict who can donate an organ, technological innovations like 3D printing and artificial kidneys, and cross-species transplantation.