Several commuter rail systems are beginning to accept mobile payments, in which tickets are purchased and validated on smartphones. Mobile payments may improve the rider experience while reducing costs and simplifying the fare collection process for rail operators. Before investing in this new ticketing technology, rail operators want to understand rider demand for mobile tickets. To assess the potential adoption of mobile payments, stated preference data from an onboard survey on two commuter rail lines (Worcester and Newburyport/Rockport) in the greater Boston area were analyzed. Binary logit was then used to forecast adoption on all commuter rail lines. Based on this model, 26 percent of commuter rail riders in Boston are very likely to adopt mobile ticketing.