Person-case constraint (PCC) phenomena involve restrictions on the relative person of the two objects of a ditransitive. In this talk, I present an account of four types of PCC patterns within the Interaction/Satisfaction theory of Agree (Deal 2015), and demonstrate some advantages of this view over various competitors. Advantages include the ability to account for both strong and weak PCC effects without invoking multiple types of Agree, and the ability to capture the rather complex relationship between PCC effects and morphological marking of Agree (i.e. in some languages PCC holds only when IO and DO clitics are combined, whereas in others PCC effects hold even though IO and DO clitics are not combined, and in still others IO and DO clitics combine without triggering PCC effects). I will also discuss the extent to which the theory can capture the role of number in PCC effects.