<p>Service planning education requires students to develop integrated competencies, particularly problem-solving skills, service planning competencies, and self-efficacy. However, traditional instructional approaches often lack structured support for engaging learners in complex, iterative problem-solving and design processes. The emergence of generative AI (GenAI) technologies, such as ChatGPT, offers new opportunities to scaffold learners’ inquiry and reflective processes; however, their application in service planning education remains limited. This study aimed to examine the effects of integrating GenAI into a 5E inquiry-based learning framework to enhance students’ problem-solving skills, service planning competencies, and self-efficacy. A quasi-experimental design was adopted involving 46 university students. Participants were divided into two groups: 22 students engaged in a GenAI-assisted 5E inquiry-based learning model, while 24 received traditional PowerPoint-based instruction. Learners’ performance was assessed across three domains: service planning competencies (rubric-based evaluation of design tasks), self-efficacy (self-reported scale), and problem-solving skills (self-reported questionnaire). Group differences were analyzed using the N-gain analysis, Mann-Whitney U test and two-way ANOVA. The results showed that the GenAI-assisted 5E inquiry group achieved significantly higher scores in service planning competencies, self-efficacy, and problem-solving skills compared to the traditional learning group. Although higher-order thinking was not directly measured, the improvements observed in problem solving and design performance suggest that the proposed approach may support aspects of higher-order cognitive processes. These findings indicate that integrating GenAI with a structured inquiry-based instructional framework can effectively enhance key competencies required in service planning education.</p>