City governments across North America are increasingly pursuing sustainability aims through novel policies and practices. Such efforts frequently involve changes to municipal services that are provided by the private sector. However, the implications of private service delivery for public sustainability aims are not well understood. We use the experience of Minnesota’s Twin Cities metropolitan area with organic waste recycling to examine how different types of public-private relationships in service delivery shape the ability of municipalities to pursue sustainability through organic waste recycling programs. We find that municipalities with contractual relationships with waste haulers – “organized” systems – have greater success in introducing organic waste recycling than municipalities with licensing relationships with waste haulers – “open” systems. These findings point to the importance of institutional variation in public-private relationships to the success of urban sustainability initiatives and the ability of decision makers to affect change.