This chapter argues that international monetary stability is an underprovided global public good under the current design of the International Monetary System. It proposes to apply the emerging doctrine of Common Concern of Humankind (Common Concern) as a methodological approach. This chapter starts by exploring the concept of monetary stability at the different levels of governance. It is followed by a description of the doctrine of Common Concern. It continues with an analysis of the three-dimensional approach proposed by this doctrine starting with the duty to cooperate in monetary affairs both from a top-down approach (international level of governance) and a bottom-up approach (central banking cooperation). The chapter continues by examining domestic obligations concerning monetary stability with an emphasis on the special role of the central banks and also by examining some cases of unilateral actions and issues of extraterritoriality in the pursuit of monetary stability. Lastly, it offers some remarks on the most controversial aspect of the doctrine that relates to securing compliance with the obligations that may emerge from an accepted Common Concern of international monetary stability.