Citizen coproduction, that is, citizens’ input to the provision of public services, holds great potential to improve services provided to citizens. It is therefore important to understand why some citizens are more likely to coproduce than others. Citizens’ skills and knowledge to coproduce are argued to be crucial for their contribution to coproduction, but research on this topic is sparse. Building on coproduction theory supplemented with theoretical insights from social psychology theory, the main contribution of this study is to develop theoretical arguments that describe how self-efficacy perception may moderate the influence of knowledge of how to coproduce on citizen coproduction undertaken by individual citizens. A large-N study in the field of education is used to examine this relation.