The global financial traumas that began in 2008 have led many nations to consider supplementing their traditional, microprudential finance-regulatory regimes with macroprudential policy instruments and, in some cases, institutions. This working paper, an early draft for what ultimately was to become an IMF Legal Department policy paper, aims systematically to address the legal and institutional considerations that any move toward macroprudential finance-regulatory policy implicates. It first considers what is involved in establishing or adapting a statutory or equivalent mandate for macroprudential finance-regulatory policy. It then turns to the harmonization of substantive macroprudential mandates with pre-existing policy regimes. Finally it considers the variety of ways in which macroprudential finance-regulatory institutions can be established or adapted in harmony with pre-existing institutions.