A kidney paired donation (KPD) is a transplant option for living kidney donors and intended recipients who are incompatible, matching them both with another donor/recipient pair that is compatible.
For example, Susan wants to donate a kidney to Juan, but they do not match. Ira wants to donate to Mercedes, but they do not match. Susan is a match for Mercedes, and Ira matches Juan. Switching donors and recipients in this case allow both transplants to happen. This type of transplant is called kidney paired donation or KPD. KPD transplants can involve two or more recipient/donor pairs, resulting in more lives saved (see diagram below):