Uber and other apps for e-hailing taxis have transformed the taxi business in recent years. However, to date, U.S. regulators have not been especially innovative in responding to the emergence of Uber and the other apps. This article analyzes what taxi regulators should be doing in the age of taxi apps, for both e-hailed taxis and traditional taxis obtained by phone, by outstretched arm on the street, and at cab stands.