A national single-payer health insurance programme in the United States could cut annual healthcare expenditure by about $1.04tn while expanding access, according to a preprint led by Yale School of Public Health researchers. The work has not yet undergone peer review, and its findings are projections rather than observed results.
The researchers modelled a programme similar to the proposed Medicare for All Act using 2024 data on spending, coverage and deaths. Their central estimate represents a reduction of nearly 20% in annual expenditure. It includes an additional $304bn for care that is currently unmet or unpaid and for universal dental services.
Five mechanisms produced the projected savings: lower medicine prices, payments to providers at Medicare rates, reduced administrative costs, less fraudulent billing and fewer avoidable emergency visits and hospital admissions. Under more cautious assumptions about medicine prices and fraud, the model still produced annual savings of at least $663bn.
The analysis also estimated that comprehensive coverage could prevent 62,863 deaths each year. Of those, 29,631 would be among people who already have insurance but face deductibles or other cost-sharing that can make treatment unaffordable. The researchers described more than 45 million working-age adults as underinsured on that basis.
A separate part of the model attributed another 51,311 preventable deaths to coverage reductions and other health-policy changes made since 2025. Combining the two estimates produced the headline projection of 114,174 lives saved annually. That total therefore depends on both universal coverage and reversal of those more recent policies.
The authors acknowledged important limits. Direct measurements of excess mortality among underinsured adults were unavailable, requiring them to estimate that risk. The spending calculation did not include the cost of moving from the existing system, possible administrative job losses or changes in provider behaviour if reimbursement shifted to Medicare levels.
The new work follows a 2020 study by some of the same researchers, published in The Lancet, that estimated $450bn in savings and more than 68,000 deaths prevented each year. The team said the larger new projections reflect higher overall spending, a wider difference between commercial and Medicare payment rates, and updated assumptions about coverage and policy.
The study adds a quantitative case to the US debate over universal insurance, but it does not demonstrate how Congress would structure or enact such a programme. Its estimates should be read as results from a specified model whose assumptions, transition effects and political feasibility require further scrutiny.
The projections concern annual system-wide effects, not guaranteed savings or outcomes for any individual patient. Future peer review could test the assumptions, methods and sensitivity analyses behind the headline totals.
