Progressive development of technology has offered varied Learning Management Systems (LMS). These systems are aimed to facilitate educational processes through the delivery of contents, assessments, learning outputs and collaborative communication. However, the acceptance of users became a determining factor for the success or failure of LMS. A comprehension of students’ acceptance towards a LMS is very essential in order to measure its use and effects. As recent model of technology acceptance, extended Unified Theory of Acceptance and Use of Technology (UTAUT 2), has been used to investigate the acceptance on ManageBac as LMS in Gandhi Memorial Intercontinental School (GMIS), Jakarta. GMIS Jakarta has used this system platform since 2012. As LMS, ManageBac has been designed to manage curriculum planning, evaluation, outcome reporting, attendance and communication. The research was aimed to prove that extended UTAUT model would be well applied at GMIS Jakarta even though with the presence of voluntariness as additional moderator. This research also had purpose to prove whether all constructs of this model affect the acceptance and use of ManageBac at GMIS Jakarta. This research employed quantitative approach with survey method using 7 scale Likert questionnaire and SEM-PLS. A total of 245 students having experience with ManageBac for more than three years were taken as participants. The result of finding revealed that ManageBac’s acceptance model was not similar to model of extended UTAUT. Moreover, this study also depicted that relations among constructs were not similar to extended UTAUT model.