Alison Galvani and colleagues1 robustly modelled the effect of the Medicare for All Act on US national health expenditures and outcomes. Spending on hospital care and physician or clinical services accounts for 53% of total spending. Their model assumes that Medicare rates are uniformly 22% lower than are private-payer rates and that, by switching all fees to Medicare rates, overall reimbursements will be 6% lower for hospitals and 7% lower for physicians.