Between 2009 and 2014, The James Irvine Foundation invested $13.4 million through the Arts Regional Initiative to build the capacity of a group of nonprofit arts organizations in California locales outside of major arts centers. The aim was two-fold: to increase cultural participation and improve financial sustainability. The following lessons, which are presented in this report, emerged from Harder+Company Community Research analysis of the Initiative: (1) It is possible to increase cultural participation; (2) Combining key approaches maximizes participation; (3) Organizations can achieve new capacities; (4) Increased capacity cannot ensure financial sustainability; (5) Partnerships and executive leadership matter; and (6) Commitment level correlates with benefit. The Initiative intentionally focused on nonprofit arts organizations working in regions of California characterized by changing demographics and lacking robust financial support for the nonprofit arts sector. The following are appended: (1) Regional Contexts; and (2) Arts Regional Initiative Phase II Grantees.