USAID Aid Cuts Projected to Reverse Two Decades of Global Mortality Decline

A comprehensive global study has concluded that United States Agency for International Development (USAID) funding has played a substantial role in reducing mortality across low- and middle-income countries (LMICs) over the past two decades, with current US policy changes threatening to reverse much of this progress.

The research, conducted by an international team led by Daniella Medeiros Cavalcanti and colleagues, combined retrospective and forecasting analyses covering 133 LMICs. Drawing on mortality, economic, and health system data between 2001 and 2021, the study estimated that USAID-supported programmes prevented approximately 91.8 million all-cause deaths, including 30.4 million in children under five.

The reductions were especially marked in mortality from HIV/AIDS (65%), malaria (51%), and neglected tropical diseases (50%). Across all age groups, USAID interventions were linked to a 15% decline in age-standardised mortality rates and a 32% decline in under-five mortality.

However, following Executive Order 14169, issued in January 2025 by the Trump administration, a substantial defunding of USAID is now underway. According to the study’s microsimulation forecasts, if the announced 83% cut in programme funding is sustained and further reductions continue until 2030, these changes could result in an additional 14 million preventable deaths, including 4.5 million children under five.

The study used a fixed-effects multivariable Poisson model, adjusted for economic, demographic, and healthcare factors, to isolate the effect of USAID per capita funding on mortality rates. The strength of the findings was confirmed through multiple sensitivity and triangulation analyses, including difference-in-differences models and negative control outcomes.

USAID’s influence, the study suggests, extended well beyond direct health interventions. Its support for sanitation, nutrition, education, and poverty alleviation also contributed to improved health outcomes. In particular, the agency funded major initiatives including the President’s Emergency Plan for AIDS Relief (PEPFAR), the President’s Malaria Initiative (PMI), and vaccine distribution through GAVI. USAID was responsible for more than $35 billion in funding in 2024, with nearly $10 billion allocated to humanitarian assistance and another $9.5 billion to health.

Between 2001 and 2021, the average USAID funding per capita rose by 97%, from $1.38 to $2.71. The study found that higher levels of funding per capita were consistently associated with lower mortality, particularly in countries with low GDP per capita, low Human Development Index, and high income inequality.

Forecasting models used in the study estimated that in 2025 alone, the funding cuts could result in approximately 1.8 million additional deaths, including nearly 690,000 child deaths. This trend is projected to accelerate in subsequent years, with cumulative excess deaths reaching over 14 million by 2030.

Particularly affected would be sub-Saharan Africa, which receives a significant proportion of USAID’s health and humanitarian aid. Already, programme suspensions have disrupted malaria control supply chains in Nigeria and Uganda, halted food assistance, and undermined local NGO capacity. The UN World Food Programme has closed its southern Africa office, and a recent survey estimated that 79 million people previously supported by USAID programmes are now without assistance.

These developments come amid a broader decline in global aid commitments. The Organisation for Economic Co-operation and Development (OECD) has projected that total development assistance could fall by up to 17% in 2025. Several European countries, including the UK, France, and the Netherlands, have already announced substantial reductions to their aid budgets.

According to the study authors, the projected health impact of USAID cuts is comparable in scale to a global pandemic or large-scale armed conflict. However, unlike those events, the authors note that this crisis would stem from a policy decision made with prior knowledge of its likely humanitarian consequences.

While limitations of the study include the potential for ecological fallacy and the inability to identify the effects of individual interventions, the authors argue that the scale and consistency of the findings support a causal interpretation. Triangulation using multiple methods, robust statistical modelling, and comparison with previous health intervention studies all reinforce the validity of the results.

In conclusion, the study highlights that the sharp reduction in USAID funding—if maintained—will likely lead to millions of avoidable deaths, particularly among the world’s poorest and youngest populations. It warns that this trend would severely undermine global efforts to achieve the Sustainable Development Goal of reducing under-five mortality to below 25 deaths per 1,000 live births by 2030.

The full study, funded by the Spanish Ministry of Science and Innovation, the UK Medical Research Council, and Horizon Europe, is now available for policymakers and stakeholders assessing the implications of the ongoing changes in US foreign assistance policy.