The concept of diversity has always been an underlying principle in media policy-making and the era of participatory media has not changed that core concern. However, dramatic changes in contemporary media systems suggest a need to reconsider how this complex principle is conceptualized and applied. Social media have brought about a seemingly infinite amount of sources and content by lowering the barriers to participation in the fields of media and communications. Much hope has been attributed to their democratizing potential. However, empirical evidence indicates that much digital media consumption focuses on content provided by few actors, and is becoming polarized. And while the rapid diffusion of new media technologies facilitates more participatory communication, persistent digital divides hinder opportunities for access and production. This article argues that diversity as a policy-making principle needs to be refocused to address these opportunities and challenges regarding the role that media systems can play in fostering citizenship, civil society and participation. Based on existing academic and public/policy discourses, the article constructs a framework of participatory modalities and discusses their relationship with the conventional dimensions of diversity, as well as their relevance in terms of policies and regulation.