We are currently making updates and improvements to the OPTN website. Data dashboards, calculators, and other interactive tools will be back online as soon as possible.
Ongoing updates
This is a sample calculator to show how the lung Composite Allocation Score (lung CAS) is established. It uses the same formula that is used for the lung allocation policy that took effect March 9, 2023. View policy notice (PDF - 1 MB).
To calculate an approximate lung Composite Allocation Score (CAS) range, enter data for each variable. If you do not have data for a variable to calculate the lung medical urgency and lung post-transplant outcomes measure, you may leave the field blank and a policy default value will be used when calculating the lung CAS. Note: the CAS may change on a daily basis.
Please note, as of March 9, 2023, the Lung Allocation Score (LAS) that was used in previous policy has been replaced by the lung Composite Allocation Score (CAS).
How your lung Composite Allocation Score (CAS) is calculated and used
Spanish and English closed captions are available in the captions menus in the bottom right of the video player.
How the calculator should be used
The lung CAS calculator is a tool that can be used to estimate each lung candidate's CAS range using various patient factors.
What the calculator isn't
The lung CAS calculator cannot accurately predict how long any patient will live with or without a transplant. It is not a definitive measure of life expectancy on the waiting list or post-transplant survival. It does not include all factors that influence survival and does not take into account any quality-of-life benefit patients may receive from transplantation. Talk to your physician or your transplant team about your specific situation.
How to calculate a lung score
When calculating the lung CAS, enter as much data as you can. You can use the Calculated Panel Reactive Antibodies (CPRA) calculator to calculate your detailed CPRA. The following guide is also available: A Guide to Calculating the Lung Composite Allocation Score (lung CAS) (PDF - 947 KB)
Lung CAS summary data
Information on the distribution of scores for all lung candidates in the U.S. as of October 27, 2025. It is intended as a point-in-time reference to help transplant programs understand how their candidates’ scores compare to the national distribution of components of the lung CAS. Members can also use this information as a guide when submitting CAS exception requests for lung candidates.
Lung CAS summary data (PDF)
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