Almost half the materials Americans discard—food scraps, yard trimmings, and soiled paper—are compostable. Municipal and county governments increasingly recognize the importance of composting. In fact, more than 250 communities have now instituted residential food scrap collection programs, up from only a handful a decade ago. Countless supermarkets, schools, restaurants, and other businesses and institutions are also source separating their food scraps for composting. This guide aims to strengthen expansion of community-scale composting by describing successful initiatives, their benefits, how these initiatives can be replicated, key start-up steps, and the need for private, public, and non-profit sector support.