A new study published in The Lancet has raised urgent concerns about the global health consequences of recent cuts to U.S. foreign aid. The study, coordinated by researchers from the Barcelona Institute for Global Health (ISGlobal), together with the Institute of Collective Health of the Federal University of Bahia (ISC-UFBA), the University of California Los Angeles (UCLA), and the Manhiça Centre for Health Research (CISM), among others, estimates that 91 million deaths were prevented between 2001 and 2021 in low- and middle-income countries (LMICs) thanks to programs supported by the United States Agency for International Development (USAID), the largest funding agency for humanitarian and development aid worldwide. However, recent U.S. foreign aid cuts could reverse this progress and lead to more than 14 million additional deaths by 2030, including over 4.5 million children under five.
“These findings come at a critical moment,” said Davide Rasella, ICREA Research Professor at ISGlobal and coordinator of the study. “The 4th International Conference on Financing for Development (FFD4), taking place this week in Seville, Spain, is a key opportunity to realign global financing with the real needs on the ground. If we want to achieve the SDGs, we cannot afford to dismantle funding mechanisms—like USAID—that have already proven to save millions of lives. Now is the time to scale up, not scale back.”
91 million lives saved
The researchers analysed data from 133 countries and combined two approaches: a retrospective evaluation covering the years 2001 to 2021, and forecasting models projecting impacts through 2030. They used statistical models that accounted for factors such as population, income, education, and health systems to estimate the effect of USAID funding on mortality, also looking at differences by age group and cause of death. Finally, they used microsimulation models to estimate how many additional deaths could occur if current funding cuts continue.
The study found that USAID-supported programs were associated with a 15% reduction in all-cause mortality and a 32% reduction in mortality among children under five. The authors estimate that more than 91 million deaths were prevented during this period, of which approximately 30 million were among children. In countries receiving high levels of support, the strongest impact was seen in priority disease areas: mortality from HIV/AIDS was reduced by 74%, malaria by 53%, and neglected tropical diseases by 51%, compared to countries with low or no USAID funding. Significant reductions were also observed in deaths caused by tuberculosis, nutritional deficiencies, diarrheal diseases, lower respiratory infections, and maternal and perinatal conditions.
“Our analysis shows that USAID funding has been an essential force in saving lives and improving health outcomes in some of the world’s most vulnerable regions over the past two decades,” says Daniella Cavalcanti, Postdoctoral Researcher at the Institute of Collective Health and first author of the study.
Millions of lives are now at risk
To estimate the future consequences of recent funding cuts, the researchers used forecasting models simulating the impact of two scenarios: continuing 2023-level funding, or implementing the sharp reductions announced in early 2025—amounting to an 83% cut to USAID programs. Their projections show that if the cuts continue, more than 14 million additional deaths could occur by 2030, including over 4.5 million among children under five, or about 700,000 extra child deaths per year. These figures reflect the projected consequences of halting funding not only for health services but also for critical sectors such as nutrition, education, water and sanitation, and humanitarian relief.
Rasella, emphasizes the scale of the risk: “Our projections indicate that these cuts could lead to a sharp increase in preventable deaths, particularly in the most fragile countries. They risk abruptly halting—and even reversing—two decades of progress in health among vulnerable populations. For many low- and middle-income countries, the resulting shock would be comparable in scale to a global pandemic or a major armed conflict.”
"From our experience on the ground, we have witnessed how USAID support has strengthened local health systems’ ability to respond to diseases like HIV, malaria, and tuberculosis. Cutting this funding now not only puts lives at risk—it also undermines critical infrastructure that has taken decades to build," concludes Francisco Saúte, General Director at the Manhiça Health Research Centre (CISM) and co-author of the study.
A global domino effect
The study warns that the impact of U.S. aid cuts could extend beyond the agency’s own programs. With the United States previously contributing over 40% of global humanitarian funding, other international donors may also reduce their commitments. This could further weaken service delivery in countries already dependent on external support.
“The findings of this study are even more concerning given that other international donors—primarily in the EU—have also announced substantial reductions in their aid budgets, potentially leading to even more additional deaths in the coming years,” adds Caterina Monti, Predoctoral Researcher at ISGlobal and one of the authors of the study.
Beyond the direct USAID support and interventions in healthcare provision, the authors highlight the importance of USAID-funded programs in improving education, food security, clean water access, and economic resilience—key elements that shape the social determinants of health. Reducing this support could undermine long-term development and stability in many LMICs.
"US citizens contribute about 17 cents per day to USAID, around $64 per year. I think most people would support continued USAID funding if they knew just how effective such a small contribution can be to saving millions of lives," says James Macinko, co-author of the study and Professor at UCLA.
The research is the first comprehensive analysis to assess the impact of total USAID funding—including support for health care, nutrition, humanitarian aid, development, education, and related sectors—on mortality rates in LMICs over the past two decades. The authors emphasize that the projections represent the most probable scenario based on currently available data and policy decisions, but that future outcomes could vary depending on how governments and institutions respond.
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