Evolution is characteristic to every Information System (IS) because of continuing changes in its environment. It is also a necessary condition for guaranteeing IS fitness to the organizational needs and requirements. Nonetheless, each IS evolution presents several risks towards its sustainability and further changes, and steering IS evolution is indispensable for any organization. In this work we propose a framework that aims to guide the actors responsible for IS evolution steering. The framework allows to reduce the uncertainty, which is inherent in the IS evolution, by providing the information necessary to realise IS evolution activities and to simulate their impact. It is composed of several conceptual models representing different IS dimensions (information, activities, regulation). In this paper we detail the IS Steering Metamodel (IS-SM), which is the main element of our framework.