This article presents the initial development of a decision support system (DSS) to assess cost impacts of upgrading or replacing a transit ticketing and fare collection (TFC) system. Assessment of these costs, typically, requires extensive calculations and involves estimation of unknown parameters such as future ridership growth rate, equipment utilization rate, and interest rate on debt financing. This DSS is developed with two categories of policy- and decision-makers in mind-transit agency manag- ers and transit industry researchers and policy-makers. With the aid of this DSS, a transit manager or analyst is able to specify current TFC system characteristics, select desirable options for a new TFC system, and in a matter of minutes estimate capital costs, forecast operating costs, perform net present value and payback period analyses for alternative TFC systems. This article also presents a prototype TFC DSS including a model base, database, knowledge base, and the Microsoft Excel-based graphical user interface.