Recent crises and the expansion of international financial arrangements have dramatically elevated the importance of cooperation between regional institutions and the International Monetary Fund (IMF). While the case for coordination between regional and multilateral institutions is generally accepted, however, the need to organize it on an ex ante basis is not fully appreciated. The relatively successful cooperation among the European Commission, European Central Bank, and IMF on the European debt crisis is not likely to be easily replicated in joint programs for countries in other regions, moreover, and the costs of coordination failure could be very large. Recent innovations at the IMF, on the other hand, present opportunities for cooperation with regional facilities. Henning reviews (1) the case for organizing cooperation on an ex ante basis, (2) the policy and institutional matters that should be coordinated, (3) how East Asian arrangements in particular and the IMF might cooperate, and (4) an Interinstitutional Agenda of general principles, modalities, and institutional recommendations. The G-20, member states, and institutions themselves should address this agenda proactively.