Assisted living (AL) communities are experiencing rising levels of resident acuity, challenging efforts to balance person-centered care—which prioritizes personhood, autonomy, and relationship-based care practices—with efforts to keep residents safe. Safety is a broad-scale problem in AL that encompasses care concerns (e.g., abuse/neglect, medication errors, inadequate staffing, and infection management) as well as resident issues (e.g., falls, elopement, and medical emergencies). Person and family engagement (PFE) is one approach to achieving a balance between person-centered care and safety. In other settings, PFE interventions have improved patient care processes, outcomes, and experiences. In this paper, we describe the protocol for a multiple methods AHRQ-funded study (Engage) to develop a toolkit for increasing resident and family engagement in AL safety. The study aims are to engage AL residents and family caregivers, AL staff, and other AL stakeholders to (1) identify common AL safety problems; (2) prioritize safety problems and identify and evaluate existing PFE interventions with the potential to address safety problems in the AL setting; and (3) develop a testable toolkit to improve PFE in AL safety. We discuss our methods, including qualitative interviews, a scoping review of existing PFE interventions, and stakeholder panel meetings that involved a Delphi priority-setting exercise. In addition to describing the protocol, we detail how we modified the protocol to address the unique challenges of the COVID-19 pandemic. Study findings will result in a toolkit to improve resident and family engagement in the safety of AL that will be tested in future research.