A field study about co-created media and design from MIT’s Co-Creation Studio finds that co-created projects are prevalent in a wide range of knowledge areas and identifies risks and emerging best practices for these projects. A common but underreported practice, co-created work is not attributable to a single author but is created collectively—either within a community, in online communities, across disciplines and organizations, or with human and algorithmic systems. The MacArthur-supported Co-Creation Studio recommends support and investment in the process of co-creation, rather than the products of it, which would help mitigate risks and support creators across areas of work.