Organizations incur substantial costs in managing organizational changes associated with the implementation of information systems (IS). However, the relationship between organizational changes and IS implementation costs is not well understood. Extending current research on IS-enabled organizational change, we draw on configuration theory to develop propositions identifying drivers of IS implementation costs. To test the propositions, we analyze the changes and implementation costs involved in three IS implementation initiatives. The analysis confirms that interdependencies between changes are key drivers of IS implementation costs. Implications for theory and practice are discussed.