The law, policy, and ethics of employers' use of financial incentives to improve health.

The Patient Protection and Affordable Care Act (ACA) turns to a nontraditional mechanism to improve public health: employer-provided financial incentives for healthy behaviors. Critics raise questions about incentive programs' effectiveness, employer involvement, and potential discrimination. We support incentive program development despite these concerns. The ACA sets the stage for a broad-based research and implementation agenda through which we can learn to structure incentive programs to not only promote public health but also address prevalent concerns.