Although mobile payments are increasingly used in some countries, they have not been adopted widely in the United States so far, despite their potential to add value for consumers and streamline the payments system. We summarize short-term and long-term benefits from mobile payments, and analyze the economic framework of that market. Both demand-side and supply-side barriers contribute to the lack of adoption of mobile payments. We contrast mobile payments at the retail point of sale in the U.S. with other countries’ experiences and with examples of successful payment innovations in the U.S. Conditions that have facilitated some success in other countries and in other U.S. innovations are not present in the mobile payments market. On the demand side, consumers and merchants are well served by the current card system and face a low expected benefit-cost ratio, at least in the short run. On the supply side, low market concentration and strong competitive forces of banks and mobile carriers make coordination of standards difficult. Furthermore, mobile payments are characterized by a network effects problem: consumers will not demand them until they know that enough merchants accept them, and merchants will not implement the technology until a critical mass of consumers justifies the cost of doing so. We present some policy recommendations that the Federal Reserve should consider.