This report was prepared by the Environmental Law Institute (ELI) with the Commons Lab at the Woodrow Wilson International Center for Scholars. It examines laws and policies that affect public decision makers’ ability to use and rely on information generated by citizen science projects. The report addresses how citizen science programs can be organized, conducted, and communicated to improve public decisions. In addition to analysis, the report compiles examples of citizen science projects in the United States that have produced changes in management decisions, enforcement actions, or the advancement of scientific knowledge useful to public officials. The Appendix contains guidance on specific legal provisions relevant to citizen science program design.