In this paper, we explore the interplay between moral expertise and moral understanding. Specifically, by focusing on moral understanding rather than on moral knowledge, whether there is a way to rethink moral expertise without embracing moral realism will be assessed. The main theoretical gain is that an understanding-based account of moral expertise can explain why moral testimony is suspicious, while the standard account cannot. In this respect, for an understanding-based account of moral expertise to really count as an alternative to realist and knowledge-based ones, some points have to be argued for: first, understanding, unlike knowledge, cannot be transmitted by testimony; second, understanding, unlike knowledge, needs to be characterized as non-factive. Both claims will be supported by referring to a sentimentalist account of moral understanding, according to which moral understanding is at least partially non-cognitive. Such an understanding-based account of moral expertise constitutes the starting point to radically rethink the notion of moral expertise and other related issues, such as moral testimony and the question regarding who are, if any, the moral experts.