Abstract
Adaptive structuration theory (AST) provides a conceptual change model that helps capture the longitudinal change process. This paper proposes a modified AST model which provides a theoretical framework that explains the appropriation process of medical electronic billing systems (MEBS). In recent years, MEBS has become a critical tool for supporting health care services. The appropriation of MEBS in a medical center involves a great deal of change, which, if not carefully considered, could result in failure. Using a case study approach, this research identifies appropriation issues when planning and evaluating MEBS usage in medical centers.