This Working Paper should not be reported as representing the views of the IMF.The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. This paper proposes a new taxonomy of monetary regimes defined by the choice and clarity of the nominal anchor. The regimes are as follows: (i) monetary nonautonomy, (ii) weak anchor, (iii) money anchor, (iv) exchange rate peg, (v) full-fledged inflation targeting, (vi) implicit price stability anchor, and (vii) inflation targeting lite. This taxonomy captures the commitment-discretion tradeoffs that lie at the heart of choosing a monetary regime. During the last 15 years the world has moved toward monetary regimes with less discretion. Empirical analysis suggests that country regime choices reflect the level of financial and economic development and recent inflation history. JEL Classification Numbers: E52, E58, E61