In health and healthcare, patients, families, and other stakeholders increasingly participate in designing, executing, and evaluating initiatives likely to affect them. Stakeholder participant roles include: (1) Advisors, as in patient/family advisory councils; (2) Co-Designers, as in participatory design team members; (3) Citizen Scientists, as in community-based participatory research; and (4) Peers, as in peer reviewers of proposed research or decisions regarding the ethics of a planned research study. This panel assembles leading US and UK human factors experts to discuss how stakeholders can be and have been involved as participants in the design, implementation, or evaluation of health or healthcare related initiatives. Panelists describe: (a) how they have involved stakeholders, describing their methods, strategies, and results; (b) associated benefits they have observed; (c) needs that have surfaced and must be addressed for successful stakeholder participation; and (d) recommendations for human factors professionals planning to involve stakeholder participants.