Many national and international public and private initiatives are forming to collect and share data on a large scale for research and clinical use. Collectively, these efforts may lead to the creation of a medical information commons, a networked environment in which diverse sources of health, medical, and genomic data on large populations become widely shared resources. The success and value of such a commons will depend on development of policies and practices for effective governance that address barriers to data sharing and are developed with informed input from patients and members of the public whose data may populate it. In an NHGRI-funded study (McGuire R01HG006460), a diverse group of experts ranked reluctance of some institutions to share data as the most important, yet least politically tractable policy challenge among 17 posed in a modified Delphi process. The objective of this proposal is to engage expert stakeholders to inform policy decisions about effective governance for data sharing, while using deliberative methods to obtain informed public input to ensure that the values, rights and interests of individuals whose data may populate the information commons are represented. In Aim 1, we will work with a multi-disciplinary expert advisory committee and con- duct a systematic landscape analysis of existing and emerging data initiatives to summarize common approaches and identify alternative models. In Aim 2, we will conduct qualitative interviews with expert stake- holders to solicit feedback on existing models and alternative approaches to key policy challenges. In Aim 3, we will use intensive deliberative methods, Citizen Panels, to solicit informed input about key policy issues, and proposed models to address them, from patients and members of the general public. This contribution will be significant because it will provide critical stakeholder input to develop the necessary foundation for a sustainable ethical and legal framework for efforts to advance public and private sector data initiatives. The approach is innovative by engaging a diverse and representative group of stakeholders, including those involved with and potentially contributing to these data initiatives, to identify policy challenges and deliberate models for effective governance. The work is feasible in our hands because our team of established investigators have expertise in ethical and policy issues related to large-scale data sharing and a track record of success working together on large collaborative projects addressing ethical and policy issues in genomics.