Purpose – The purpose of this paper is to improve the general operationalization of an “active patient,” by examining the specific activities and skills expected of active patients. Design/methodology/approach – Expected activities and necessary skills were studied through a qualitative case study into the development and use of an assistive technology (i.e. web site) aimed at stimulating active patient-ship. Interviews, observations and document analysis were used to capture and explore designers’ inscribing practices and their consequences regarding expected competences and activities of patients using the web site. Findings – Designers inscribed two “co-design roles” that active patients were expected to perform on the web site (co-designing their own healthcare and co-designing the healthcare of peers), for which at least eight different competencies were needed. The absence of skills or facilities to apply these skills resulted in incomplete use, a different use than intended by designers and non-use of the web site. Practical implications – Technological choices and inscribing processes determine who is able or facilitated to become active and who is not. Due to inscribed co-design roles, it also influences the extent to which already active peers are able to perform health-related activities. Different users with different conditions should be taken into account in the design as specific group characteristics can influence level of individual activity. Originality/value – This study is, as far as the authors know, the first that examines the “active patient” concept by studying an assistive technology and using scripting literature, resulting in an improved understanding of what it means to become “active” in terms of skills and activities.