The advancement of information and technology resulted in the change in conventional test methods. The weaknesses of the paper-based test can be minimized using the computer-based test (CBT). The development of a CBT desperately needs a computerized item bank. This study aimed to develop a computerized item bank for classroom and school-based assessments. A research and development method is used in this study, which consisted of four phases, i.e., planning, item development, system development, and field testing. Data is collected through documentation, expert judgment, and field testing. The data were analyzed using descriptive statistics and item response theory. The sample of this study was teachers and high school students in West Sumatera province selected using purposive random sampling techniques. The results of the study are as follows. 1) The computerized item bank has excellent quality based on expert validation. 2) There are 120 items inputted into the item bank system that has a moderate difficulty and good discriminant index based on item response theory. 3) The field testing indicated the computerized economics item banking has high effectiveness of usability, usefulness for the teachers, and feasible for classroom and school-based assessment.