259 Background: Patients with cancer and their caregivers often describe the fragmented, multi-modal and multi-provider cancer care experience as undertaking a difficult expedition without a map. Based on her experience in 2020 and using self and family management theories (doi: 10.1016/j.outlook.2008.10.004.), Daswani developed a pan-cancer patient planner, which helps patients and families prepare for appointments, track symptoms, and manage their care. It has been available since 2021 through hospitals, advocacy organizations and online retail channels. We adapted and customized the pan-cancer planner for patients with mNSCLC. We tested acceptability through a series of structured patient interviews, and a brief, in-person survey tool. Methods: A lung cancer survivor recruited members of the lung cancer community to participate in a 30-minute structured virtual interview. After reviewing the planner, interviewees were asked: 1) about their diagnosis and treatment experience and 2) to provide semi-structured feedback. We conducted interviews until thematic saturation was reached. We modified the planner based on interview results, distributed planners to patients and care-partners at a major lung cancer patient summit and immediately collected a brief survey to assess patient knowledge of their diagnosis and motivation for planner access. Results: The table shows high level thematic groups of interview responses. Interviewed patients concluded that the planner would have improved their experience because they would have: Stayed organized, facilitated note-taking during appointments, better tracked and managed symptoms & meds, been more confident in decision-making and been able to journal, stay grounded and more mindful. Of 94 planners distributed at the summit, 49 patients knew their diagnosis, 31 knew their stage, 28 knew their cancer mutation status. Of the four domains of self-management, positive responses were: 1. Increase confidence 44 (47%) 2. Gain peace of mind 40 (43%) 3. Stay organized 58 (62%) 4. Manage meds & symptoms 42 (45%). Conclusions: A paper based mNSCLC specific planner is acceptable to patients and they anticipate it would help with all four domains of self management (confidence, peace of mind, organization, med and symptom management) and enhance a difficult experience. We plan further usability testing as we did with the breast cancer planner (JCO Oncol Pract 19, 2023 (suppl 11; abstr 552)). Interviews of 8 (7 female, 1 male) patients (3 with English as a second language) were held in December 2023. Diagnosis Biomarker Testing Treatment Living with lung cancer Medical terms difficult to understand “Mutation” term caused anxiety Understanding options important Need for community Diagnosis often delayed Loss of agency Gratitude for care team Digital tools desired Cumulative trauma Additional languages Young adult survivorship desired