Transplant Education

1. 1
   Evaluation

   Your medical team refers you to a transplant center where specialists assess whether you are a candidate for transplant. This includes blood work, imaging, cardiac testing, and psychosocial evaluation. The process typically takes several weeks.

2. 2
   Listing

   Once approved, your transplant center registers you on the national waiting list managed by the United Network for Organ Sharing (UNOS). You can be listed at more than one center simultaneously, known as multiple listing.

3. 3
   Waiting

   While on the waitlist, your medical team monitors your health and updates your status. Wait times vary dramatically by organ type, blood type, geographic region, and medical urgency. During this time, staying healthy and reachable is critical.

4. 4
   Transplant

   When a compatible organ becomes available, the transplant team notifies you and the surgery is performed, often within hours. The organ is matched based on medical compatibility, urgency, wait time, and geographic proximity to the donor.

5. 5
   Recovery

   After surgery, you will spend time in the hospital for monitoring, followed by a structured outpatient recovery. Lifelong immunosuppressive medications are required to prevent rejection. Regular follow-up visits track graft function and overall health.

Organ allocation in the United States is managed by UNOS under contract with the federal government through the Organ Procurement and Transplantation Network (OPTN). Allocation policies aim to balance medical urgency, fairness, and efficient use of donated organs.

Several factors affect your position and likelihood of receiving an organ:

• Organ type: Each organ has its own allocation system with different prioritization criteria.
• Blood type: ABO compatibility between donor and recipient is required. Blood type O patients often wait longest because O organs are compatible with all recipients.
• Medical urgency: Sicker patients generally receive higher priority, though the specific scoring varies by organ.
• Time on the waiting list: Accumulated wait time is a factor, especially for kidney allocation.
• Geographic proximity: Distance is measured in nautical miles from the donor hospital to the hospital where you are listed. Donation Service Areas and OPTN regions were removed from allocation between 2020 and 2021 and replaced with distance-based circles or, for lung, a weighted distance component.
• Your program's own decisions: Whether a center lists you, and whether it accepts an organ offered on your behalf, are decided by the program rather than by OPTN policy. See our FAQ on what your program decides.

Organ-specific scoring systems:

• MELD (Model for End-Stage Liver Disease): Used for liver allocation. A score from 6 to 40 based on lab values (bilirubin, INR, creatinine, sodium). Higher scores indicate greater illness severity and higher priority.
• CAS (Composite Allocation Score): Used for lung allocation since March 9, 2023, replacing the Lung Allocation Score. Adds up weighted points for medical urgency, expected post-transplant survival, biological disadvantage such as blood type and height, placement efficiency (distance from the donor hospital), pediatric priority, and prior living donor status.
• cPRA (Calculated Panel Reactive Antibodies): Used in kidney allocation. Measures how sensitized a patient is to donor antigens. Higher cPRA (0-100%) means fewer compatible donors but also earns additional priority points.

For organ-specific allocation rules and scoring systems, see our Organ Guides.

UNOS

United Network for Organ Sharing. The private nonprofit that manages the U.S. organ transplant system under federal contract. Maintains the national waiting list and develops allocation policies.

OPTN

Organ Procurement and Transplantation Network. The federal framework established by Congress in 1984 to oversee organ transplantation. UNOS has operated OPTN under contract since its inception.

SRTR

Scientific Registry of Transplant Recipients. Provides statistical analyses of transplant program performance, including wait times, patient and graft survival, and organ offer acceptance rates. Their reports are a key tool for comparing transplant centers.

OPO

Organ Procurement Organization. Regional organizations responsible for coordinating organ donation in their designated service areas. There are 56 OPOs in the United States.

DSA

Donation Service Area. The geographic region served by a single OPO. Organs were once offered within the donor's DSA before expanding to wider regions, but DSAs and OPTN regions were removed from allocation between 2020 and 2021 in favor of distance measured from the donor hospital. You will still see the term in older documents and in some SRTR reporting.

MELD

Model for End-Stage Liver Disease. A numerical score (6-40) used to prioritize liver transplant candidates based on how urgently they need a transplant. Calculated from bilirubin, INR, creatinine, and sodium lab values.

CAS

Composite Allocation Score. The score used to prioritize lung transplant candidates since March 9, 2023. It sums weighted points across medical urgency, expected post-transplant survival, biological disadvantage, placement efficiency, pediatric priority, and prior living donor status. It replaced the Lung Allocation Score (LAS), which balanced urgency against expected benefit alone and which you will still see referenced in older material.

AOOS

Allocation Out of OPTN Sequence. Placing an organ outside the strict match-run order, typically when an organ is at risk of not being placed. The accepting center chooses the recipient from its own candidates. The rules governing this are being rewritten following a February 2025 HRSA directive.

ILDA

Independent Living Donor Advocate. A person every program performing living-donor transplants must provide to represent the donor's interests, required by 42 CFR 482.98(d) and OPTN policy. The advocate must not be routinely involved in the program's transplant activities.

cPRA

Calculated Panel Reactive Antibodies. A percentage (0-100%) indicating how sensitized a kidney transplant candidate is to potential donors. Highly sensitized patients (high cPRA) receive additional allocation priority to offset their smaller compatible donor pool.

DCD

Donation after Circulatory Death. Organ donation that occurs after cardiac death rather than brain death. DCD donors are an increasing source of transplantable organs, though with some differences in organ viability compared to brain-dead donors.

HCV+

Hepatitis C Virus Positive. Refers to donors who test positive for hepatitis C. Advances in direct-acting antiviral treatments have made HCV+ organs viable for many recipients, expanding the donor pool significantly.

Graft Survival

The length of time a transplanted organ continues to function after transplant. Measured at standard intervals (1-year, 3-year, 5-year). A key outcome metric for comparing transplant center performance.

Waitlist Mortality

The rate at which patients die while waiting for a transplant. A critical metric for understanding the gap between organ supply and demand, and for evaluating regional differences in access.

Have questions about these terms? See our FAQ for detailed explanations.

Use our Find My Centers tool to find the best center for your needs, or compare centers side by side.

The Scientific Registry of Transplant Recipients (SRTR) publishes Program-Specific Reports (PSRs) for every transplant center in the United States. These reports are the primary way to compare center performance using standardized metrics.

Key elements of a center-level SRTR report:

SRTR reports rate each center as performing "better than expected," "as expected," or "worse than expected" compared to a risk-adjusted national average. No single metric tells the full story, so it is important to consider all dimensions together and discuss the data with your transplant team.