Until recently, warfarin was the only oral anticoagulant (OAC) available in the US, and a substantial infrastructure has developed around its management. Over the past five years, four non-Vitamin-K antagonist oral anticoagulants (NOAC) have been approved by the FDA. The NOACs are associated with generally fewer and less severe bleeding complications, and shorter half-lives, often making management of bleeding that complicates the use of these agents less problematic than similar episodes associated with warfarin. Bleeding during NOAC therapy does occur, and patients taking NOACs sometimes require procedures that cannot be delayed, for which good hemostasis is desirable, and therefore the NOAC may delay or complicate care. The challenge of this latter issue is compounded by the lack of readily available, rapid-turnaround quantitative assays for measuring the magnitude of anticoagulation effect associated with NOAC use. From a safety perspective, the large warfarin infrastructure does not translate into useful support for use of the new NOACs; their anticoagulation impact cannot be readily monitored by simple, quick tests.