From 2012 to 2018, the Exploring Engagement Fund of The James Irvine Foundation provided risk capital for more than 100 engagement projects conducted by California arts nonprofits. These organizations had innovative ideas and a readiness to take bold steps to engage groups often underrepresented among mainstream arts participants--specifically people of color and low-income residents. The Foundation's goal was to promote arts engagement for all Californians, with the belief that arts provide a distinct, powerful, and public benefit that helps create a vibrant, inclusive, and compassionate society. This goal also aligns with the intent of many California arts organizations to engage participants and artists who reflect the socioeconomic diversity of the state's population. This evaluation highlights the meaningful impact Exploring Engagement Fund projects had on participating community members, project partners, and the grantees themselves. It also confirms the original hypothesis of the initiative: Diverse participants are more likely to take part in more active forms of arts engagement. Further, it yields a rich set of insights, best practices, and considerations for nonprofit arts organizations and funders. [This report was written in partnership with Diane Espaldon. For the full report, see ED604066.]