Four databases of citizen science and crowdsourcing projects —  SciStarter, the Citizen Science Association (CSA), CitSci.org, and the Woodrow Wilson International Center for Scholars (the Wilson Center Commons Lab) — are working on a common project metadata schema to support data sharing with the goal of maintaining accurate and up to date information about citizen science projects.  The federal government is joining this conversation with a cross-agency effort to promote citizen science and crowdsourcing as a tool to advance agency missions. Specifically, the White House Office of Science and Technology Policy (OSTP), in collaboration with the U.S. Federal Community of Practice for Citizen Science and Crowdsourcing (FCPCCS),is compiling an Open Innovation Toolkit containing resources for federal employees hoping to implement citizen science and crowdsourcing projects. Navigation through this toolkit will be facilitated in part through a system of metadata tags. In addition, the Open Innovation Toolkit will link to the Wilson Center’s database of federal citizen science and crowdsourcing projects.These groups became aware of their complementary efforts and the shared challenge of developing project metadata tags, which gave rise to the need of a workshop.   On July 9th & 10th, 2015, a Citizen Science & Crowdsourcing Metadata Workshop was hosted by the Wilson Center's Commons Lab in coordination with the U.S. Environmental Protection Agency and the Federal Community of Practice on Crowdsourcing and Citizen Science. The results of this workshop included 30 fields describing citizen science project metadata (found in the Appendix of the workshop summary). Seven of these fields will be applied in a demonstration of data sharing between four databases. However, the current list of project metadata tags requires expansion, especially around concepts related to crowdsourcing.  This publication is a summary of the results from the workshop and a definition of the collaboration moving forward.