Skip to main content


In the United States, the United Network for Organ Sharing (UNOS) is the national organization that sets policy and enforces the rules for organ allocation. UNOS rules determine when and to whom organs are allocated. All transplant centers must abide by UNOS rules to remain certified to perform transplants. UNOS divides the country into 11 distinct organ sharing regions as shown on this map.


We have a unique opportunity to make our voices heard and to bring about an important change. This is an urgent call to action. PSC Partners supports the proposed UNOS policy change. Every comment by PSC patients and caregivers is important. Add your voice today! Visit this page on our website for more information.

Educational Toolkit for the PSC Community: Communicating Transplant Concerns to UNOS

PSC patients and caregivers may want to learn more about the current U.S. system of organ allocation or have concerns about how PSCers fare. The United Network for Organ Sharing (UNOS) schedules public comment sessions to hear concerns and other feedback, and this toolkit may be helpful if one plans to comment. PSC Partners prepared it so that the PSC community might understand the liver allocation system and how it works; advocate for a system that fairly prioritizes PSC without creating inequities for other liver disease patients; and be able to clearly articulate concerns during the UNOS public comment sessions. 

The UNOS Tool Kit has more information.

The UNOS Summer 2020 Public Comment Session concluded on Oct. 1, 2020.

Hopefully there will be a future UNOS open comment session.

The information contained in the toolkit above can help you prepare for that important event.


MELD/PELD: For liver candidates, UNOS has developed a scoring system called MELD (Model End-Stage Liver Disease) to determine the need for a liver. The scoring system is based upon blood tests for bilirubin, creatinine, and INR (International Normalized Ratio, also called prothrombin time). MELD scoring also includes serum sodium levels.  Scores range from 6 (low level of illness) to 40 (gravely ill). For persons under the age of 12, the calculator is called PELD (Pediatric End-Stage Liver Disease). The PELD score includes age, bilirubin, albumin, INR, and history of growth failure. 

The MELD/PELD system has reduced the number of deaths of people on the waiting list by offering livers for the sickest patients. Researchers have found that transplantation too early, at a low MELD score, can prematurely expose the person receiving the transplant to higher operative and immunosuppressive risks associated with the transplant surgery.

Waiting Time: The waiting time for liver transplantation varies depending on how sick the individual is, which is usually reflected by their MELD or PELD score. In addition, blood type is also important in the matching process, and body type may play a role. Until 2002, time spent on the waiting list was the determining factor for organ recipients. However, today the MELD and PELD scores identify who is sickest and requires a liver first.

Special Exceptions: For some liver conditions, a special exception can be made to raise the MELD/PELD score. If your doctor thinks you present special circumstances that are unaddressed by the MELD/PELD system, the transplant center can ask the National Liver Review Board (NLRB) for an exception. Exceptions are very rarely given. The hepatologist with whom you are working can explain where you fit in the scoring system.

MELD/PELD Calculators

The UNOS website has a calculation feature page where you can calculate the MELD and PELD score, if you know the values of certain recent blood tests.

Updating Lab Tests: As you get closer to your transplant, you will be required to update blood tests on a specific, required schedule. If you do not keep the tests updated and inform your transplant center, you can be given a lower MELD/PELD score until you get your lab tests done. Your center’s transplant coordinator will help you understand the schedule and assist you in sending the results to the center.

Complete your profile and join PSC Partners Seeking a Cure in advancing PSC research towards a cure. Find information about clinical trials.