In this chapter, I tackle a deficit of current modus vivendi theory, namely its neglect of institutions. Modus vivendi theorists have good reason to get beyond this position and show how the notion of modus vivendi politics can be made use of for considerations about institutional design. First, I argue that two features of modus vivendi enable critical assessments of institutional design: modus vivendi arrangements are supposed to reflect the plurality of views on disputed issues and find the acceptance of those who are subject to the arrangement in question. Second, I apply these criteria of modus vivendi to recent institutional innovations that have been implemented in order to strengthen the capacity of pluralist democracies to deal with deep disagreements: (a) the release of parliamentarians' duty to vote in line with their parliamentary groups and the establishment of (b) ethics councils and (c) mini-publics. The requirements of modus vivendi politics enable both a critique of these institutions and the development of alternative designs. I make an exemplar case for this claim by sketching a fourth possible institutional innovation: flexible negotiating forums.