<p>The topic of disagreement has captured a great deal of attention among epistemologists in recent years. In this paper, I want to raise the issue of disagreement for the epistemic aim of understanding. I will address three main issues. The first concerns the <i>nature</i> of understanding disagreement. What do disagreements in understanding amount to? What kind of disagreement is at play when two agents understand something differently, or have a different understanding of something? The second concerns the <i>norms</i> of rational epistemic behavior in dealing with understanding disagreements. How should an agent react in realizing that another agent understands things differently than she does? The third concerns the <i>value</i> of understanding disagreements. Are understanding disagreements valuable? What is there to gain from understanding disagreements, and what is there to learn from those who understand things differently than we do? My arguments lend support to three main theses. The first is that understanding disagreements are interestingly different from familiar doxastic disagreements. The second is that reasonable understanding disagreements are possible, and hence that we are often entitled to stand our ground in face of an understanding disagreement. The third is that understanding disagreements can have epistemic value, because they can lead to modal insight.</p>