We examined trends in US public health expenditures by analyzing historical and projected National Health Expenditure Accounts data. Per-capita public health spending (inflation-adjusted) rose from $39 in 1960 to $281 in 2008, and has fallen by 9.3% since then. Public health’s share of total health expenditures rose from 1.36% in 1960 to 3.18% in 2002, then fell to 2.65% in 2014; it is projected to fall to 2.40% in 2023. Public health spending has declined, potentially undermining prevention and weakening responses to health inequalities and new health threats.