Idiosyncratic deals (i-deals) are customized work arrangements that employees negotiate with their employer. Despite the burgeoning growth, i-deals research is primarily focused on the benefits to the recipients without sufficiently considering how differences in i-deals across group members can have implications at the group and individual levels. To better guide the nascent literature, we (a) conceptualize content, quantity, and magnitude as the three key bases upon which i-deals can differ; (b) explain why content of i-deals can reflect social or economic exchange; and (c) define relative i-deals, that is, how individual group members' i-deals compare to coworkers, and group i-deals differentiation, that is, the degree of variability in team member i-deals, in actual and perceptual terms. In our multilevel theory development of differences in i-deals, we offer propositions on (a) effects of perceived relative i-deals on outcomes at the individual level, (b) effects of actual and perceived group i-deals differentiation on outcomes at the group level, and (c) perceived group i-deals differentiation as a moderator of the effects of perceived relative i-deals at the individual level. Lastly, we conclude with managerial implications and future directions for research.