This Article argues that federal health care reform may induce employers to redesign their health plans to encourage high-risk employees to opt out of employer-provided coverage and instead acquire coverage on the individual market. It shows that such a strategy can reduce employer health care expenditures without substantially harming either high-risk or low-risk employees. Although largely overlooked in public policy debates, employer dumping of high-risk employees may threaten the sustainability of health care reform. In particular, it potentially exposes individual insurance markets and insurance exchanges to adverse selection caused by the entrance of a disproportionately high-risk segment of the population. This risk, in turn, threatens to indirectly increase the cost to the federal government of subsidizing coverage for qualified individuals and to exempt more individuals from complying with the so-called individual mandate. The Article concludes by offering several potential solutions to the threat of employer dumping of high-risk employees.