Sustaining AI-Enabled Student Support: A Four-Year Implementation and Impact Study

AI-enabled chatbots are increasingly used to support student success, yet evidence on their long-term sustainability and impacts remains limited. We examine the implementation of an AI-enabled text-messaging chatbot at a large, urban public university. Drawing on system observation, discussions with administrators, and a four-year randomized controlled trial, we assess institutional conditions for sustained implementation, student receptivity over time, and effects on academic outcomes. We find that centralized ownership and flexible communication are critical for sustainability. Students remain receptive over time, and impacts are concentrated in improved completion of time-sensitive administrative tasks, with no detectable effects on academic performance or persistence.