This article makes three contributions to participatory design (PD) research and practice with vulnerable groups: 1) a framework for understanding stakeholder engagement over the course of a PD project; 2) approaches to making user engagement and PD activities more inclusive; and 3) an analysis of how the design and power dynamics of PD projects affect vulnerable groups’ participation. A map of engagement is developed to evaluate stakeholder involvement from initial problem definition to design outcome. The map is applied to three projects aimed at increasing inclusion of vulnerable groups in the planning of public sector services. The first looks at codesign activities to support decision-making in the context of intellectual disabilities; the second looks at culturally diverse youth navigating crisis without adequate assistance from public services; and the third examines nursing students adapting to work in the health sector without accommodations for learning disabilities. Comparing the projects reveals patterns in project planning and execution, and in stakeholder relationships. The article analyses how users are defined, engaged and supported in PD; how proxies shape vulnerable groups’ involvement and PD projects as a whole; and opportunities for greater inclusion when the entire PD project is taken into account.