Current policy
Every lung transplant candidate receives an individualized lung Composite Allocation Score (CAS). This score determines priority for receiving a lung transplant when donor lung(s) become available. The lung CAS is individual for each candidate and each organ offer. The lung CAS point values represent each of the factors used to match organ offers with transplant candidates (Exhibit 1). The people who have the highest number of points for that organ offer will have the highest priority.
In October 2025, the Health Resources and Services Administration’s (HRSA) preliminary analyses documented a rise in allocation out of OPTN sequence (AOOS) that correlates with the implementation of the lung continuous distribution policy in 2023. In response, the OPTN Board of Directors considered potential changes to lung allocation to promote policy compliance and reduce AOOS.
Note: Certain changes described in this proposal were previously implemented following emergency action by the OPTN Board of Directors and are currently in effect while the proposal proceeds through the formal policy process.
Supporting media
Exhibit 1. Current Lung Composite Allocation Score
| Attribute | Definition | % of Available Points |
|---|---|---|
| Waiting List Survival | Expected 1-year waiting list survival | 25 |
| Post-Transplant Outcomes | Expected 5-year post-transplant survival | 25 |
| Candidate Biology | Total of ABO, CPRA, and height points | 15 |
| ABO | Based on percentage of compatible donors by blood type | 5 |
| CPRA | Based on percentage of compatible donors by CPRA | 5 |
| Height | Based on percentage of compatible donors by height | 5 |
| Patient Access | Total of pediatric and prior living donor points | 25 |
| Pediatric | For candidates under 18 years old | 20 |
| Prior Living Donor | For candidates who donated any organ | 5 |
| Placement Efficiency | Total of travel and proximity efficiency points | 10 |
| Travel Efficiency | Based on impact of distance on costs of travel | 5 |
| Proximity Efficiency | Based on impact of distance on other efficiency (time, availability, etc.) | 5 |
Note. Total Score = Waiting List Survival + Post-Transplant Outcomes + Candidate Biology + Patient Access + Placement Efficiency
Acronyms. ABO=ABO blood group system, CPRA=Calculated Panel Reactive Antibody
Proposed changes
- Increasing the weight on placement efficiency from 10% to 15% of the overall score.
- Reducing the weight on all other parts of the score proportionally, including points assigned to pediatric candidates less than 12 years old for waitlist survival and post-transplant outcomes.
- Replacing the existing travel efficiency and proximity efficiency rating scales with a single placement efficiency rating scale to assign points to potential transplant recipients based on the nautical mile distance between the donor hospital and the transplant hospital.
- Lung CAS scores for all lung and heart-lung candidates on the waiting list will be updated to reflect the changes to the lung CAS (Exhibit 2).
- Approved exceptions will remain in effect based on the percentage of available points approved by the Lung Review Board, and the points assigned for each exception will be reduced proportionately to the adjusted goal weights.
Exhibit 2. Revised Lung Composite Allocation Score
| Attribute | Definition | % of Available Points |
|---|---|---|
| Waiting List Survival | Expected 1-year waiting list survival | 23.6111 |
| Post-Transplant Outcomes | Expected 5-year post-transplant survival | 23.6111 |
| Candidate Biology | Total of ABO, CPRA, and height points | 14.1666 |
| ABO | Based on percentage of compatible donors by blood type | 4.7222 |
| CPRA | Based on percentage of compatible donors by CPRA | 4.7222 |
| Height | Based on percentage of compatible donors by height | 4.7222 |
| Patient Access | Total of pediatric and prior living donor points | 23.6111 |
| Pediatric | For candidates under 18 years old | 18.8889 |
| Prior Living Donor | For candidates who donated any organ | 4.7222 |
| Placement Efficiency | Total of travel and proximity efficiency points | 15 |
Note. Total Score = Waiting List Survival + Post-Transplant Outcomes + Candidate Biology + Patient Access + Placement Efficiency
Acronyms. ABO=ABO blood group system, CPRA=Calculated Panel Reactive Antibody
Anticipated impact
- What it's expected to do
- Reduce median travel distance for lungs
- Reduce logistical complexity in lung allocation
- Improve policy compliance
- What it won’t do
- It will not completely alleviate AOOS.
Terms to know
- Allocation out of OPTN sequence (AOOS): An organ allocation event in which an organ is offered, accepted, and/or transplanted outside the established match sequence.
- Composite Allocation Score (CAS): This score determines priority for receiving a lung transplant when donor lung(s) become available.
- Calculated Panel Reactive Antibody (CPRA): A score (0–100%) indicating the percentage of potential donors a patient is immunologically incompatible with due to antibodies.
Read the full proposal (PDF - 354 KB)
Submit a Comment
I appreciate that you are addressing the growing issue of allocations occurring outside the OPTN sequence, as this continues to erode trust among the public and within non‑transplant medical communities. I believe waiting‑list survival should remain at 25 points, but prior living donors should receive more than the current 4.7 points. Living donors have made an extraordinary contribution at significant personal risk, and the system should offer a stronger safety net if they later need a transplant themselves. While it does not guarantee an organ, increased priority acknowledges their sacrifice, supports fairness, and encourages future living donation. Strengthening protections for living donors ultimately promotes long‑term trust and sustainability within the donation system.
Sara Broderick Cooper
Swannanoa, NC
Relationship to Lung Transplant: Community member and Advocate
Regarding the November 20, 2025 OPTN Board meeting vote to alter the Lung Transplant Continuous Allocation Score (CAS) points and ratios in order to address concerns about Allocation out of Sequence (AOOS).
I am writing to express my strong desire for HRSA/OPTN Board to reverse the decision voted in during the November 20, 2025 Board meeting to remove five points from the biological disadvantage category and reallocate them to the efficiency category, returning the CAS point allocation and ratios to the pre November 23, 2025 vote levels.
This matters to me because I have a friend who are in need of lung transplant.
Additionally, I share the concerns expressed by the Lung Transplant Foundation letter directed to HRSA and the OPTN Board of Directors, submitted via the Critical Comments and Directives Pathway on April 13, 2026, and signed on to by seventeen distinct lung disease patient advocacy organizations, identifying the following primary concern areas as reasons to oppose this change to the CAS:
- Bucking decades of protocol, no prospective public comment period occurred before this major policy change, and no clinical evidence was supplied justifying the use of the emergency pathway at the time of the vote.
- No clinical rationale was given for ignoring the recommendation of the Lung Committee, which unanimously opposed this change to the CAS, and no solutions were proposed to address the concern that initial modeling suggested that these changes would increase the waitlist mortality for high-risk individuals.
- The change in protocol from extensive modeling before policy changes are implemented to minimal modeling with an intention of catching problems after they occur will endanger lives unnecessarily.
- Patient voices and specialized lung transplant expert opinion should be centered at every stage of OPTN policy development, including the identification of problems, proposed solutions, and the implementation of new policy geared at addressing identified problems.
Thank you again for the opportunity to comment. I sincerely hope that, upon reviewing the newly available data and the consistent and unanimous dissent from lung transplant professionals, lung transplant candidates/recipients, and community members, HRSA and the OPTN Board of Directors will reverse the November 20, 2025 vote and restore the CAS to its previous point and ratio allocation.
Sincerely,
Sara Broderick Cooper
I look forward to the results of regular review of allocation success and especially for mitigation of the targeted concerns to assess the impact of these changes. We all hope unintended adverse consequences are not revealed at the same time. Meanwhile, I return a concern I raised two decades ago about "continuous" distribution which relies on categorical rings of distance without adjustment for edge effects. In the intervening years, computing power and coding sophistication has grown exponentially. Modeled calculation of cold ischemic time to every potential destination will eliminate the categorical rings, but only a priori weighting, such as the modifications done with this patch, can incrementally improve geographic equity and justice as required by the Final Rule.