This paper introduces EFTeacher, an AI chatbot based on GPT-4-Turbo. EFTeacher aims to reduce delay discounting (the tendency to undervalue delayed rewards for immediate gratification) and promote health behavior change by inducing episodic future thinking (EFT), which vividly imagines individuals’ future events and experiences. The researchers evaluated the feasibility and usability of EFTeacher through a mixed-methods study that included a usability evaluation, a content-specific questionnaire-based user evaluation, and semi-structured interviews. As a result, EFTeacher was perceived as communicative and supportive by the participants through engaging conversations, and it was found to promote imaginative thinking and reflection on future goals. However, Limitations, such as repetitive conversations and long-winded responses, were also raised.