Despite extraordinary scientific and medical resources, the US health-care system underperforms. In this Review we consider the damage wrought by decades of market-based policies that have stimulated profit-seeking by insurers and health-care providers. Policy makers have subcontracted coverage under the public Medicaid and Medicare programmes for people with low incomes and those older than 64 years to private insurance firms—which now derive most of their revenues from those programmes—raising taxpayers’ costs and constricting patients’ care. Despite worrisome evidence of misbehaviour, firms obligated to prioritise shareholders’ interests—and, more recently, private equity firms with a single-minded focus on short-term profit—have gained control of vital clinical resources. President Biden rescinded some of Donald Trump's most egregious first-term policies, expanded coverage for lower-income Americans, and initiated modest drug price controls. Since regaining office, President Trump has laid siege to science and public health, cut US$990 billion from Medicaid to offset tax reductions for the wealthy, and is accelerating Medicare's privatisation. State governments can tighten regulation of profit-driven abuses, and the medical community should resist Trump's health-harming agenda. But neither restoring the pre-Trump status quo, nor further attempts to reconcile the human rights of patients with the property claims of investors will suffice. Reforms must, instead, decommercialise insurance and care provision.