In Seeking Solidarity, Turner et al consider the opportunities and choices that make city-wide union movements more or less likely to shift towards community unionism and practice labour-community coalitions (Turner and Cornfield forthcoming). This paper takes a narrower frame of analysis – the single local union – and considers the opportunities and choices that influence likely community unionism practice. Community unionism is defined as the range of strategies that involve unions 'reaching out' to the community. These include labor-community coalitions (reaching out to community groups), broadening the frame of union campaigns to embrace 'community concern' (reaching out to community issues), and campaigns that seek to control place (reaching out to local communities). The paper builds a typology of factors that suggest when community unionism, or union collaboration with the community, is likely to develop. It first considers an 'opportunity structure' including environmental/economic context, union identity, structure and characteristics and union relationships. Secondly it considers the internal choices that unions make, noting the organisational, identity/interest and scale dimensions of union agency. I conclude that a union is most likely to undertake collaboration with the community when its accesses and embodies the 'attributes of community' in both its opportunity structure and choices. It explores this framework with reference to the shift to community unionism using examples from the Australian and US union movements.