How we match organs

UNOS serves as a vital link in the organ transplant process, matching donor organs with transplant candidates to save lives.

Organ matching policies are developed by volunteer committees of donation and transplant professionals, recipients, donor families and other members of the community, and approved by the OPTN Board of Directors. These policies are then programmed into the UNOS computerized matching system. Only medical and logistical factors are used in organ matching. Personal or social characteristics such as celebrity status, income or insurance coverage play no role in transplant priority.

Before an organ is allocated, all transplant candidates on the waiting list that are incompatible with the donor because of blood type, height, weight and other medical factors are automatically screened from any potential matches. Then, UNOS’ computer system, UNet, determines the order that the other candidates will receive offers. Community-developed policy determines the order of organ offers made to transplant programs.

How organ matching works

When a transplant hospital accepts a person as a transplant candidate, it enters medical data—information such as the person’s blood type and medical urgency and the location of the transplant hospital—about that candidate into UNOS’ computerized network. When an organ procurement organization gets consent for an organ donor, it also enters medical data—information such as the donor’s blood type and body size and the location of the donor hospital—into UNOS’ network.

Using the combination of donor and candidate information, the UNOS computer system generates a “match run,” a rank-order list of candidates to be offered each organ. This match is unique to each donor and each organ. The candidates who will appear highest in the ranking are those who are in most urgent need of the transplant, and/or those most likely to have the best chance of survival if transplanted.

Frequently asked questions