As a public resource, the PSI-2 has special regulations and policies designed to make the PSI results beneficial to the broad scientific community. From the inception, PSI required rapid release of all results, including the deposition and release of coordinates and related information into the PDB. The PSI-2 centers are not funded by the usual research grants mechanism, but via cooperative agreements. Each Principal Investigator is responsible for directing his/her center, but all centers are required to work together and NIH staff and outside advisors share important roles in determining program goals and actions. The PSI-2 centers are also responsible for outreach activities—to the scientific community, to minority scientists and students, and for research training. As a network with joint activities and goals, the centers are continually discussing and fine-tuning issues such as target selection, management, operation, and cooperation. The PSI Steering Committee is the internal governing body of PSI-2, composed of the PSI center directors, four NIH staff, and five outside scientists. It is responsible for setting goals and the implementation of plans and overall project operation within the framework established by the PSIAC and the NIGMS Advisory Council. The PSI annual meetings and annual PSI-sponsored “Bottlenecks” meetings bring the PSI scientists, advisors, and NIH staff together to discuss technical hurdles, progress, plans, and strategies. Both are open meetings and participation of scientists outside the PSI is encouraged. As a major NIH project intended to serve as a scientific resource, questions of policy and goals are discussed regularly by those involved with the PSI. Input from the broad scientific community is crucial to this initiative.More information on the history and background, plus summaries of PSI workshops, and program announcements, goals, and requirements and progress of the initiative are available on the NIGMS/PSI website at http://www.nih.gov/nigms/funding/psi.html. In keeping with general policies regarding its larger grants programs, the NIGMS is conducting an assessment of the PSI program, with a report due in early 2008. This assessment will focus on how well the PSI has achieved the goals originally developed for the program as well as notable achievements and challenges. This assessment is one source of input that will guide NIGMS in considering potential future initiatives related to structural biology, but others modes of input will also be utilized. Optimizing the potential future impact of structural biology on biomedicine depends on a balanced approach to infrastructure support, technology development, structure determination, and the integration of structure and function.