What is it to share the same concept? The question is an important one since sharing the same concept explains our ability to non accidentally coordinate on the same topic over time and between individuals. Moreover, concept identity grounds key logical relations among thought contents such as same saying, contradiction, validity, and entailment. Finally, an account of concept identity is crucial to explaining and justifying epistemic efforts to better understand the precise contents of our thoughts. The key question, then, is what psychological and social facts could play these roles? Elsewhere, we have argued for a specific relational model of concept identity, the connectedness model (e.g. Schroeter 2012, Schroeter and Schroeter 2014, 2015). Our aim in this paper is to further explain the motivations behind that account, to address worries about transitivity and vagueness, and to contrast our approach with closely related accounts of concept identity developed by François Recanati and Simon Prosser. What’s distinctive of our approach is that we seek to vindicate the first-person epistemic perspective of concept users. Concepts, on our account, play a crucial normative role in setting regulative ideals for the representational practices in which individual subjects participate. This focus on the normative role of concepts – as opposed to a purely causal explanatory role –motivates our approach to concept identity and our toleration of vagueness and borderline cases.