Introduction: Transitions from the adult intensive care unit (ICU) to other care settings can be challenging for patients, families, and healthcare providers, with risks to communication, care continuity, and psychosocial well-being. Objective: We aimed to codevelop patient- and family-centred resources to educate, empower, and engage adult ICU patients and their families during their ICU-to-ward and ICU-to-home transitions, supporting them as informed partners in their care journey. Methods: Building on previously published scoping reviews and end-user input that identified 76 candidate ICU transition resources, we used a two-phase, user-centred approach to develop a transitions in care (TiC) Bundle. Phase 1: Using an adapted Appraisal of Guidelines for Research and Evaluation II process, which supports structured evaluation of health-related resources, and a multidisciplinary prioritisation exercise involving patients, families, and healthcare providers, we refined and organised content into four sections: A Guide to the ICU, How is My Loved One Doing?, Going Home from the ICU, and Going to Another Unit. Phase 2: We conducted three iterative cycles of usability testing with ICU patients/families (n = 15) and clinicians (n = 18). Content analysis guided revisions addressing readability, terminology, workflow fit, and content gaps. Results: Patients and families valued practical checklists and guidance on “what to ask” during transitions. Clinicians appreciated the bundle's simplicity, consistent layout, mental health focus, support group info, and QR-code references. Suggested improvements included clarifying resource use, detailing ward-based disciplines, and better explaining delirium. Integration into workflows (printing, documentation, and off-hour transfers) was a key consideration. Conclusions: The TiC Bundle is a user-informed resource designed to address communication and psychosocial needs during ICU transitions. Future work will focus on feasibility and acceptability testing, with attention to how the resource influences patient and family experience, care continuity, and communication.