The national organ donation and transplant system

How UNOS, OPOs and transplant programs work together to save lives

About UNOS

UNOS is a nonprofit organization focused on saving and transforming lives. The federal government has awarded UNOS a contract to manage the nation’s organ donation and transplant system through the Organ Procurement and Transplantation Network since 1986.

As an OPTN contractor, every day, UNOS works for the more than 100,000 patients on the transplant waiting list to ensure they have equitable access to lifesaving organs no matter where they live or where they go for their transplant care.

About OPOs

Organ Procurement Organizations (OPOs) are nonprofit organizations responsible for recovering organs from deceased donors for transplantation in the U.S. There are 55 OPOs, each mandated by federal law to perform this life-saving mission in the donation service area (DSA) assigned to them.

OPOs are on the front-line of organ procurement, and work directly with a decedent’s family during the emotional discussion about the potential donation of the gift of life.

When an OPO receives consent for an organ donation, it enters medical data, such as the donor’s blood type and body size and the location of the donor hospital, into UNet^SM, the secure web-based platform UNOS developed to connect OPOs and transplant hospitals, which then initiates the organ matching process with potential recipients.

For every successful match, the OPO facilitates authorization, testing, the recovery of the donor organs and delivery to the transplant hospital.

About transplant hospitals

Physicians refer potential end stage organ failure patients to the more than 250 transplant hospitals in the U.S. Diagnostic medical testing as well as consideration of a patient’s mental health and social support system are considered during evaluation. Transplant hospitals use this information to determine whether or not to add patients to the national waiting list.

When a transplant hospital accepts a patient as a transplant candidate, it enters medical data such as the person’s blood type and medical urgency into UNet^SM.

Matching donors and transplant candidates

If a hospital accepts a patient as a candidate for transplant, the candidate is not immediately placed on a ranked list. Rather, his or her information is maintained in UNet^SM. Each time an organ becomes available, using organ-specific allocation algorithms derived from OPTN allocation policies and the combination of donor and candidate information, UNet^SM generates a match run, a rank-order list of candidates to be offered each organ.

This match is based on allocation policies developed by the community and approved by the OPTN board of directors. It 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.

Patients’ transplant physicians may accept or decline organ offers based on cold ischemia time, the donor’s age or medical history and many other factors.

UNet^SM is accessible to the donation and transplant community 24 hours a day, seven days a week, where UNOS Organ Center staff, as part of the OPTN contract, are available around the clock to answer questions and assist with organ placement.

In 2024, more than 48,000 transplants were performed in the U.S., thanks to the gifts of life from more than 16,900 deceased donors and more than 7,000 living donors.

Working together to drive continuous improvement

As an OPTN contractor, UNOS works collaboratively with the donation and transplant community to make the transplant system more efficient and effective to save more lives. As a community dedicated to preserving the gift of life, our shared goals are:

• Increasing organ utilization
• Enhancing process efficiency
• Improving equity in access to transplant