Atrial fibrillation (AF) is a major risk factor for stroke, and for decades the anticoagulant warfarin was the standard treatment for lowering that hazard. However, numerous drug and food interactions make warfarin burdensome for patients. A new class of drugs—non–vitamin K antagonist oral anticoagulants (NOACs)—have emerged as an alternative that is more effective as well as less burdensome. But these drugs also come with a higher price tag than generic warfarin.