In this article, we examine the methodology that should be applied to design a social innovation through a service based on a digital platform implementation to improve benefit statement digitalization. The method of stakeholders' inclusion, the triangulation methodology, and the citizen-centered service design are the main approaches discussed in it. The key outcome will be the discussion of a research agenda to design a citizen-centered service, deployed as a digital platform, through social innovation in a complex ecosystem. This process addresses both governance decisions on the future of the service regarding what type of entity should take over the current structure and with what objectives and technological decisions around infrastructure and standards, in implementing this service.