2.1.1 Characteristics of waitlist candidates

In 2024, there were 3,780 new adult candidates added to the lung transplant waiting list—the highest recorded in a single year and a 53.5% increase from 2013 (Figure LU 1). Over the course of the year, 4,713 candidates were on the waiting list at any given time, with 8.0% of them temporarily inactive (Figure LU 2 and Figure LU 11). Of these candidates, 96.4% were awaiting their first lung transplant while 3.6% were listed for a retransplant (Figure LU 10). Alongside the observed growth in the number of candidates, their demographic profile has been gradually evolving. The population continues to age. In 2024, individuals aged 50 years or older accounted for 83.7% of the waiting list. Notably, the proportion of candidates aged 65 years and older nearly matched the traditionally dominant 50- to 64-year age group (Figure LU 3). Shifts in other demographic characteristics also emerged. The distribution by sex moved toward male predominance, with male candidates increasing from approximately half of the list in 2013 to 56.7% in 2024 (Figure LU 4). White candidates continued to make up the majority of the lung transplant waiting list in 2024, accounting for 65.2%. However, this represented a 20.1% decline since 2013, during which time the racial and ethnic composition of the list has become more diverse. In 2024, Hispanic candidates made up 14.7% of the waiting list and Black candidates represented 12.3% (Figure LU 5).

Waitlist trends by diagnosis group remained mostly consistent. At the extremes, candidates in diagnosis group D made up the majority of the waiting list at 69.7%, while the proportion of candidates in group C continued its decline—a trend that began in 2019—reaching just 1.5% of the list in 2024. This decline is largely attributed to the widespread use of cystic fibrosis transmembrane conductance regulator modulator therapies in the United States. Candidates in diagnosis group A made up 21.9% of the list, and group B accounted for 6.9% (Figure LU 6).

Key biological characteristics that affect candidate-donor matching, and therefore candidates’ access to transplant, include height, blood type, and cPRA value. The distribution of height and blood type in this population has remained largely stable over time. In 2024, adults with height <150 cm (<59 in) represented the smallest proportion at 3.3% of the waiting list; those 150-<160 cm (59-<63 in), 16.2%; those 160-<170 cm (63-<67 in), 31.5%; those 170-<180 cm (67-<71 in), 32.1%; and those 180 cm or taller (71 in or taller), 16.9% of the waiting list (Figure LU 8). Blood type O candidates continued to represent the highest proportion of the waiting list at 51.1%, followed by type A at 35.5%, type B at 10.5%, and type AB at 3.0% (Figure LU 9). Data on cPRA are not reported here because the data are missing not at random. Currently, unacceptable antigens are entered by transplant programs primarily to maximize the number of donors screened for a candidate, rather than to accurately represent the candidate’s true degree of sensitization. As a result, reported cPRA values are not reliable for comparative and population-level analysis.

The waitlisted population in 2024 was notably sicker than a decade before, which may reflect both advances in transplant programs’ ability to manage medically complex patients and a broader application of lung transplant as a therapeutic option. Medical urgency for lung transplant candidates is quantified by the estimated risk of mortality within the next year without a transplant, expressed as the waitlist area under the curve (WLAUC; range, 0-365 days). In 2024, the sickest transplant candidates who had a WLAUC of <210 days made up 26.1% of the waiting list (compared with 17.1% in 2015); otherwise, 14.8% had a WLAUC of 210-<300 days, 23.1% had a WLAUC of 300-<335 days, and 35.9% had a WLAUC of 335 days or more (Figure LU 12).

In addition to biological characteristics and waitlist urgency, a candidate’s likelihood of long-term survival within the first 5 years after transplant—expressed as the posttransplant area under the curve (PTAUC; range, 0-1,826 days)—is incorporated into the CAS. By the end of 2024, there were 27.4% of candidates on the list who had a PTAUC of <1,360 days, 28.5% had a PTAUC of 1,360-<1,430 days, 24.2% had a PTAUC of 1,430-<1,485 days, and 19.9% had a PTAUC of 1,485 days or more (Table LU 2). Because prior lung allocation systems did not include long-term posttransplant survival, the trends of these values over time have yet to be seen.

2.1.2 Outcomes of waitlist candidates

In 2024, the deceased donor lung transplant rate for adult candidates reached the highest level to date, at 351.7 transplants per 100 patient-years—more than a threefold increase since 2013 (Figure LU 13). As transplant rates have risen, waiting times have markedly declined. In 2024, for candidates on the waiting list, 67.9% received a transplant within 3 months of listing; 77.6%, within 6 months; and 84.6%, within 1 year—compared to just 43.2%, 56.0%, and 65.3% in 2013, respectively; this represents a remarkable improvement (Figure LU 19). Longer-term outcomes of candidates newly listed in 2019-2021 are shown in Figure LU 20. Among those candidates, 78.6% underwent transplant within 1 year, 8.8% remained on the list, 8.0% were removed for other reasons, and 4.6% died. By 2 years, those numbers were 82.4%, 2.8%, 9.9%, and 4.9%, respectively. At 3 years, the proportions were similar, highlighting that most candidates who undergo transplant do so within the first year.

Transplant rates have increased across all age groups since 2013 and generally continue to rise each year; however, they plateaued from 2022 through 2024 for candidates aged 65 years and older. This trend may reflect the broader policy impacts associated with the implementation of CAS, particularly its emphasis on estimated long-term posttransplant survival in determining access to transplant. In 2024, transplant rates were highest among candidates aged 50-64 years (372.7 transplants per 100-patient-years), followed by those aged 35-49 years (366.5) and 65 years and older (339.5), then were lowest among the youngest adult candidates (262.7) (Figure LU 14). By race and ethnicity, transplant rates have been lowest among Black candidates for the past several years, a trend that persisted in 2024 with a rate of 249.6 transplants per 100 patient-years. This compared with 552.0 transplants per 100 patient-years for candidates in the Other racial and ethnic category, followed by 365.8 for White, 362.0 for Hispanic, and 336.3 for Asian candidates (Figure LU 15). Note that the “Other” category includes Multiracial individuals, Native American candidates, and those with unreported race and ethnicity, constituting only 4.0% of candidates (Figure LU 5). Due to the small sample size, estimates for this group are unstable and are subject to wide year-to-year variation.

Transplant rates varied across adult diagnosis groups in 2024 as they have in the past, with group D having the highest rate at 421.2 transplants per 100 patient-years, followed by group C at 343.6, group A at 266.5, and group B at 157.7 (Figure LU 16). While these rates have mostly increased over time for candidates in all diagnosis groups, there was a decline in rates for candidates in group B between 2023 and 2024. Close monitoring is needed to determine whether this represents a true trend or a spurious fluctuation. Candidate biological characteristics influence donor matching and, consequently, access to transplant, as evidenced by divergent transplant rate trends by blood type and height. Transplant rates have varied by blood type over the past decade, with the most pronounced divergence beginning in 2023. In 2024, candidates with blood type AB had the highest transplant rate at 907.9 transplants per 100-patient-years, while those with type O had the lowest at 271.4 (Figure LU 17). Similarly, the tallest candidates (180 cm [71 in] or taller) continued to have the highest transplant rates in 2024, with rates declining as heights decreased (Figure LU 18). However, a notable shift occurred among the shortest candidates (<150 cm [<59 in]), whose transplant rates exceeded those of the next tallest group (150-<160 cm [59-<63 in]) starting in 2023 and continuing to 2024. This reversal is likely attributable to the CAS, which assigns disproportionately higher biological disadvantage points to individuals with extremely short stature. It is important to emphasize that these differences only represent disparities in transplant access if equally sick candidates are unable to access transplant at comparable rates due to their biological characteristics. Therefore, transplant rates by blood type and height should not be considered in isolation but rather as potential contributors to inequity in access.

Pretransplant mortality rates have decreased modestly over the years: 16.2 deaths per 100 patient-years in 2024 compared with 18.2 in 2013 (Figure LU 21). Notably, following implementation of lung continuous distribution in 2023, mortality rates initially declined to 13.4 deaths per 100 patient-years but subsequently increased in 2024. This pattern can be observed after the adoption of allocation systems that prioritize the most medically urgent candidates—such as lung continuous distribution, which enables broader geographic access to donor organs for the sickest individuals. As these high-acuity candidates rapidly receive transplant and are removed from the waiting list, the remaining cohort may temporarily reflect a lower severity of illness, leading to short-term variability in observed mortality rates. The uptick in 2024 may represent an artifact of this redistribution and recalibration period. Ongoing data will clarify the longer-term trends and impact of continuous distribution on pretransplant mortality rates.

Since 2023, pretransplant mortality rates have largely converged for age groups, remaining within a relatively narrow range of 13.9 to 18.4 deaths per 100 patient-years in 2024 (Figure LU 22). There was variation in pretransplant mortality by race and ethnicity, but almost all groups had a decline in mortality since the pre-CAS era in 2022—the exception being Asian candidates, whose mortality increased from 21.0 to 31.1 deaths per 100 patient-years (Figure LU 23). The higher observed pretransplant mortality among Asian candidates may be influenced by their smaller population size (only 3.8% of all candidates) (Figure LU 5), which can result in year-to-year variability and unstable estimates. Nonetheless, this trend warrants careful monitoring. Male candidates have historically had higher pretransplant mortality rates. Although the mortality rates for male and female candidates briefly converged in 2023, they diverged again in 2024 at 18.1 deaths per 100 patient-years for male candidates and 14.5 for female candidates (Figure LU 24).

Pretransplant mortality rates by diagnosis group have generally followed a consistent pattern. In 2024, group D continued to have the highest mortality rate of 20.0 deaths per 100 patient-years, followed by group B at 12.6, group A at 9.5, and group C at 5.7 (Figure LU 25). Group C had a sharp decline in mortality beginning in 2019, reaching a remarkable milestone of zero deaths in 2023. However, this trend reversed in 2024. This shift may reflect unstable estimates due to group C accounting for only 1.5% of the waiting list, or it may signal an emerging trend of a sicker cohort of patients with cystic fibrosis who need a transplant, in an era where cystic fibrosis transmembrane conductance regulator modulator therapies are delaying or reducing the need for a lung transplant in this population (Figure LU 6 and Figure LU 25).

In 2024, mortality rates by blood type mostly converged, though the rate was slightly lower for those with blood type AB. Note that these rates are calculated based on time spent on the waiting list. Because candidates with blood type AB had the highest transplant rate and thus the shortest waiting time, their lower mortality reflects reduced time at risk rather than inherently better outcomes on the waiting list (Figure LU 17 and Figure LU 26). Pretransplant mortality rates also converged in 2024 for candidates across most height groups, with the exception of the 150-<160 cm (59-<63 in) group, who had the highest mortality at 19.1 deaths per 100 patient-years (Figure LU 27). This finding may reflect a gap in how biological disadvantage is quantified for this group, who likely face similar challenges in donor size matching but do not receive the same prioritization as candidates in the adjacent shorter height category.

As expected from the waitlist risk prediction models, the highest pretransplant mortality rate (135.8 deaths per 100 patient-years) was observed among the sickest candidates with a WLAUC of <210 days (Figure LU 28). Mortality rates decreased substantially with increasing WLAUC: 23.4 for 210-<300 days, 12.0 for 300-<335 days, and 7.5 for candidates with WLAUC of 335 days or more. Note that although the current waitlist population is sicker than a decade ago—with candidates in the <210-day WLAUC category representing 26.1% of the list compared with 17.0% a decade ago—pretransplant mortality for this group has declined by 36.6%, to 135.8 deaths per 100-patient years in 2024 from 214.3 in 2015. By PTAUC, pretransplant mortality followed a clear stepwise pattern, with the highest rates among candidates with the lowest predicted posttransplant survival (Table LU 4). The mortality rate was 26.4 deaths per 100 patient-years for those with a PTAUC of <1,360 days, decreasing to 16.4 for 1,360-<1,430 days, 10.8 for 1,430-<1485 days, and 9.4 for those with a PTAUC of 1,485 days or more.

Finally, among candidates removed from the waiting list for reasons other than transplant or death, 23.6% died within 6 months after removal (Figure LU 29). Reflecting the demographic distribution of the waiting list, the highest postremoval mortality occurred in candidates in diagnosis group D (32.0%; Figure LU 30), those aged 65 years or older (38.2%; Figure LU 31), White candidates (28.0%; Figure LU 32), and male candidates (27.2%; Figure LU 33).

2.2.1 Characteristics of transplant recipients

In 2024, the United States performed more lung transplants than in any prior year with a total of 3,404 transplants, including adult, pediatric, and multiorgan procedures (Figure LU 34). Of these, 3,375 were adult lung transplants, an increase of 326 from the year before (Figure LU 35). Bilateral lung transplant continued to far outnumber single lung procedures, although the latter remains a viable and consistently used option, accounting for 595 transplants in 2024—a figure that has remained relatively stable since 2013 (Figure LU 36).

The age distribution of lung transplant recipients continued to reflect the aging candidate population. Individuals aged 50 years or older accounted for 84.4% of transplant recipients, closely mirroring their 83.7% representation on the waiting list (Figure LU 3 and Figure LU 37). Since 2022, transplant recipients aged 50-64 years and those aged 65 years or older have made up roughly equal proportions of transplant recipients. In 2024, more lung transplants were performed in male than female recipients: 2,012 and 1,363 transplants, respectively (Figure LU 38). By race and ethnicity, transplant recipients reflected the demographic makeup of the waiting list: White recipients accounted for 67.2% of transplants and made up 65.2% of the waiting list, followed by Hispanic, Black, Asian, unreported, Multiracial, and Native American recipients (Figure LU 5 and Figure LU 39).

Transplant trends by diagnosis remained largely stable over the past 5 years, with a continued steep rise for recipients in diagnosis group D, a modest increase for group A, and stable patterns for groups B and C (Figure LU 41). In 2024, group D recipients accounted for 2,496 transplants (74.0% of all transplants); group A, for 676 (20.0%); group B, for 152 (4.5%); and group C, for 51 (1.5%) (Figure LU 41). Of the 3,375 adult lung transplants performed in 2024, 102 (3.0%) transplants were part of multiorgan transplants: 58 heart-lung, 25 liver-lung, 15 kidney-lung, and 4 other multiorgan (Table LU 9).

The CAS distribution among transplant recipients (including the efficiency subcomponent) was 13.4% with CAS < 29, 18.0% with 29-<31, 36.4% with 31-<36, and 29.9% with a CAS of 36 or higher (Table LU 8). Recipients were distributed across urgency categories as follows: 31.6% had a WLAUC of <210 days; 14.8%, a WLAUC of 210-<300 days; 21.4%, a WLAUC of 300-<335 days; and 32.2%, a WLAUC of 335 days or more (Figure LU 42 and Table LU 8). Compared with prior years, the largest increases in transplant proportions were observed among the sickest (WLAUC of <210 days) and the least urgent (WLAUC of 335 days or more) recipients, a trend that first emerged in 2023. Although this pattern may seem counterintuitive—because transplant rates did not decline in a stepwise fashion with decreasing urgency—it is reassuring that pretransplant mortality did follow a steep, stepwise decline with increasing WLAUC, particularly between the groups with WLAUC of < 210 and 210-<300 days (Figure LU 28). Note that waitlist urgency is only one of the four major drivers of allocation for adults under lung continuous distribution, alongside predicted posttransplant survival (ie, PTAUC), biological disadvantage (blood type, height, and cPRA), and geographic distance between donor and recipient hospitals. In fact, transplant recipient distribution by PTAUC did not show a clear trend favoring candidates projected to live longer. Specifically, 27.1% of recipients had a PTAUC of <1,360 days; 25.8%, a PTAUC of 1,360-<1,430 days; 23.6%, a PTAUC of 1,430-<1485 days; and 23.5%, a PTAUC of 1,485 days or more (Table LU 8). These emerging patterns warrant close monitoring as lung continuous distribution continues to evolve.

Finally, the highly selected population of lung transplant recipients had an exceptionally high rate of health insurance coverage in 2024, with 95.7% insured and only 4.3% categorized as other/unknown coverage. The vast majority of recipients (82.5%) lived in metropolitan areas. Half of all candidates lived within 50 miles of their transplant center, while 10.7% traveled 250 miles or more to their center (Table LU 7).

The number of centers performing lung transplants (adult or pediatric) rose to 74 in 2024 (Figure LU 46). With rising national transplant volumes, more centers are now operating at higher capacity: 7 centers performed 101 or more transplants, 9 performed 76-100 transplants, and 14 performed 51-75 transplants—compared to just 2, 3, and 5 centers in these respective categories in 2013 (Figure LU 47).

2.2.2 Outcomes of transplant recipients

Mortality among adult lung transplant recipients has shown modest improvement in early survival over the past decade, with 6-month death rates declining from a high of 8.6% for transplants in 2014 to 6.8% for transplants in 2023 (Figure LU 48). One-year mortality has similarly decreased in recent years, reaching 9.4% for transplants in 2023. Long-term outcomes have remained relatively stable, with 3-year mortality (transplants in 2013-2021) ranging from 25.3% to 29.3% and 5-year mortality (transplants in 2013-2019) ranging from 38.9% to 40.8%. Ten-year mortality, available only for the 2013 and 2014 cohorts, exceeded 67%, highlighting the persistent challenges in improving long-term survival following lung transplant.

For those who underwent transplant in 2017-2019, the 1-year patient survival was 89.2%, 3-year patient survival was 73.6%, and 5-year patient survival was 60.1% (Figure LU 49). Survival rates varied by age group, with younger recipients consistently demonstrating higher long-term survival. At 1-year posttransplant, survival was at or nearly 90% for all age groups, except those aged 65 years and older who were at 87.5% (Figure LU 50). By 3 years, survival declined to 76.4% for the youngest groups (18-34 and 35-49 years) and 75.8% for recipients aged 50-64 years but dropped more steeply to 69.2% for recipients aged 65 years and older. At 5 years, the survival gap widened further: 66.0% for recipients aged 18-34 years and 66.6% for those aged 35-49 years, compared with 62.7% for those aged 50-64 years and only 53.0% for those aged 65 years and older. These patterns underscore age as a strong predictor of long-term outcomes after lung transplant, with notably lower 5-year survival among older recipients—a trend also demonstrated in risk-adjusted analyses in the scientific literature.

Patient survival for transplants in 2017-2019 was generally similar across sex (Figure LU 53) and most racial and ethnic groups, except that Asian transplant recipients had higher 5-year survival at 66.8% compared with ranging from 59.7% to 61.8% in the other groups (Figure LU 51). In terms of diagnosis groups, group C had the highest unadjusted 5-year survival at 71.5%, versus ranging from 57.8% to 61.3% in the other diagnosis groups (Figure LU 52).

Finally, immunosuppression use among adult lung transplant recipients remained consistent. Induction agents were used in 88.6% of recipients in 2024, up from 56.9% in 2013, reflecting the nearly universal adoption of this strategy in recent practice (Figure LU 43). Interleukin-2 receptor antibody (IL2Ab) agents alone accounted for 85.0% of all induction therapies administered, followed by T-cell–depleting agents at 2.6%, and combined IL2Ab plus T-cell-depleting agents at 1.0% (Figure LU 44). Maintenance immunosuppression continued to be dominated by triple-drug therapy, with tacrolimus, mycophenolate, and steroids used in 87.9% of regimens (Figure LU 45). The incidence of acute rejection in the first year after transplant remained tightly clustered, between 8.1% and 11.5% in 2023 (Figure LU 55). Among recipients who were Epstein-Barr virus (EBV) negative, the incidence of posttransplant lymphoproliferative disorder (PTLD) was 7.5% by 5 years after transplant, compared with a lower incidence of 1.2% among EBV-positive recipients (Figure LU 57).

4.1.1 Characteristics of waitlist candidates

In 2024, the number of pediatric candidates on the lung waiting list reached its lowest point in the past decade at 62 (Figure LU 71), with 42 new candidates added during the year (Figure LU 70). Among candidates classified as pediatric at listing, most were aged 12-17 years (54.8%), followed by those aged 6-11 years (29.0%), those aged 1-5 years (11.3%), those 18 years or older (3.2%), and those younger than 1 year (1.6%) (Figure LU 72). The waitlist composition by race and ethnicity was 56.5% White, 24.2% Hispanic, 9.7% Other, 6.5% Black, and 3.2% Asian (Figure LU 73). For distribution by sex, 58.1% of candidates were male (Figure LU 74). Lung disease diagnosis among pediatric lung transplant waitlist candidates has changed over the past few years, with a decrease in the proportion with cystic fibrosis and an increase in the proportion with pulmonary hypertension (Table LU 12). A third of waitlist candidates in 2024 lived more than 250 miles from the transplant center (Table LU 11).

4.1.2 Outcomes of waitlist candidates

Among pediatric candidates on the waiting list, 48.4% were listed for less than 90 days, 12.9% for 3-<6 months, 17.7% for 6-<12 months, and 21.0% waited for 1 year or more (Figure LU 75). The deceased donor lung transplant rates continued to increase to 133.5 transplants per 100 patient-years in 2024, from a low of 76.8 in 2022 (Figure LU 76). Transplant rates were highest for candidates younger than 1 year, followed by those aged 12-17 years, 6-11 years, and 1-5 years (Figure LU 77). Although transplant rates by race and ethnicity are shown, it is difficult to interpret trends for transplant access by this characteristic in the pediatric population because the numbers are small in each category (Figure LU 78). Among pediatric candidates newly listed in 2019-2021, at 1 year, 59.9% had undergone transplant, 10.7% had died, 17.5% had been removed from the list for other reasons, and 11.9% were still waiting (Figure LU 79).

In 2024, the pediatric pretransplant mortality rate decreased to its lowest point: 3.9 deaths per 100 patient-years (Figure LU 80). Pretransplant mortality was only observed among the candidates aged 12-17 years, at 9.9 deaths per 100 patient-years (Figure LU 81). In 2024, no pediatric candidates died while on the waiting list, five were removed due to having improved, and three were removed for being too sick for transplant (Table LU 15).

4.2.1 Characteristics of transplant recipients

In 2024, there were 29 pediatric lung transplants performed (Figure LU 82): 21 recipients aged 12-17 years, 6 recipients aged 6-11 years, 1 recipient aged 1-5 years, and 1 recipient younger than 1 year (Table LU 16 and Figure LU 83). By race and ethnicity, 16 recipients were White; 8, Hispanic; 2, Black; 1, Asian; and 1, Multiracial (Table LU 16). Most of the recipients had private insurance (58.6%), followed by Medicaid (34.5%) and Medicare (3.4%). The distance between the donor hospital and the transplant center was more than 500 miles in 58.6% of cases (Figure LU 84 and Table LU 16).

For cause of lung disease, most pediatric transplant recipients were in the other/unknown diagnosis category (n = 20), followed by pulmonary hypertension (n = 4), pulmonary fibrosis (n = 3), cystic fibrosis (n = 1), and other vascular (n = 1); the cystic fibrosis group has continued to decrease over the past few years. At the time of transplant, four candidates were supported with mechanical ventilation and extracorporeal membrane oxygenation (ECMO) and mechanical ventilation, two with ECMO only, and one with mechanical ventilation only (Table LU 17). In 2024, 89.7% of recipients received a lung-alone transplant and 10.3% received a heart-lung transplant. In 2024, there was one pediatric retransplant (Table LU 18). The combination of a donor who was positive for cytomegalovirus and a pediatric recipient who was negative occurred in 30.9% of recipients. The combination of a donor who was positive for EBV and a pediatric recipient who was negative occurred in 28.4% of recipients (Table LU 19).

4.2.2 Outcomes of transplant recipients

As in previous years, in 2024, most pediatric lung transplant recipients (89.7%) received induction therapy (Figure LU 85), with 51.7% receiving T-cell–depleting agents only and 37.9% receiving IL2Ab agents only (Figure LU 86). There was an increase in the proportion of transplant recipients who were maintained on a regimen of tacrolimus, mycophenolate, and prednisone to 79.3% in 2024 (from 67.7% in 2023) and a decrease in the proportion on tacrolimus and mycophenolate to 10.3% in 2024 (from 19.4% in 2023) (Figure LU 87). Although it remained a relatively uncommon occurrence, for transplants in 2013-2019, PTLD was higher at 5 years for EBV-negative recipients at 7.5% than for EBV-positive recipients at 1.8% (Figure LU 90). Patient death among pediatric lung transplant recipients was 16.1% at 6 months and 19.4% at 1 year for transplants in 2023, 28.0% at 3 years for transplants in 2021, 44.2% at 5 years for transplants in 2019, and 62.7% at 10 years for transplants in 2014 (Figure LU 88). For those who underwent transplant in 2017-2019, 89.8% of pediatric lung transplant recipients survived to 1 year, 62.8% survived to 3 years, and 54.7% survived to 5 years (Figure LU 89).