Organ transplant waiting list

The availability of an organ for an organ transplant may be unpredictable. If you are on the waiting list for an organ transplant, you may be called at any time with news that a potential donor has been found who may be a "match"
for you.

Learning what it means to have a "match" may help you understand why it can take a long time to find a suitable organ. Each of your cells has antigens, which act as your cells' identification cards. These antigens tell your body that the cells belong to you. If a cell is in your body with an identification card that doesn’t match yours, your body may reject it. That's why it is so important to find an organ with antigens similar to yours.

There is a system to help ensure that patients who need a transplant are given priority, based on a variety of factors. This system is managed by the United Network for Organ Sharing, or UNOS. UNOS coordinates efforts among transplant centers across the nation to allocate donated organs. The UNOS Web site has more information on this system and is available at

If you are not sure if you are on the waiting list for an organ, talk to your transplant coordinator. It may help to stay connected with your transplant coordinator so you can stay up-to-date on whether a donor may become available for you.

If you move or change any of your phone numbers, it would be a good idea to tell the transplant center so that they can reach you right away if a “match” is found
for you.

Your position on the waiting list may depend on blood type, tissue type, antibodies, crossmatch, and length of time you have been on the waiting list.

Blood type
(O, A, B, or AB

Blood type must be compatible whether you are receiving a living or deceased donor organ

  • If your blood type is:
  • O
  • A
  • B
  • AB
  • Your donor’s blood type could be:
  • O
  • A or O
  • B or O
  • A, B, AB, or O

Tissue type

There are six antigens (markers) found in your blood sample. A perfect match occurs when all six antigens match the donor.


Your immune system may produce antibodies that act specifically against something in the donor’s tissues.


A test to see if there is anything in your blood that will react against the donor’s cells.


Every time an organ becomes available, a list of patients who might be compatible is generated. If you are not a perfect match with the donor, the organ is allocated based on the closest match and your time on the waiting list.