Whether the disclosure of genetic (and non-genetic) information should be mandatory or voluntary is of concern. At present there are two opposing camps--the insurance industry argues for mandatory disclosure to avoid problems of adverse selection, and genetic interest groups argue for voluntary disclosure, fearing discrimination and public reluctance to have tests, thus missing out on any benefits from subsequent interventions. Policy has to balance these sides of the debate, as reducing adverse selection and encouraging maximum take-up of tests are both important for public health. We outline why voluntary disclosure is the optimal policy as it creates an incentive for people both to undergo testing and to disclose their result thus reducing the potential for adverse section.