Prior to the fourth meeting, the PI and two members of the project Working Group participated in a session on return of IFs and IRRs at the annual meeting of the International Society for Biological and Environmental Repositories (ISBER), to elicit input from attendees. Our project then held a day-long public conference in Bethesda, MD, presenting our project’s draft recommendations and individual papers to elicit further feedback. The day after the conference, the Working Group met a fourth time to further refine our recommendations in light of feedback received. Final revisions to these recommendations were negotiated by e-mail. As is common in consensus papers produced by large multi-disciplinary author groups, individual authors may not agree with every point made below. However, the authors reached consensus on the thrust of this paper and the paper’s recommendations.