Abstract Among individuals and communities with low-income, the experience of food insecurity is associated with greater delays in recommended mammography screening and late-stage breast cancer at diagnosis. Community-based interventions that address barriers to breast cancer screening in diverse communities of women with food insecurity can increase screening uptake, ultimately improving cancer health equity. In partnership with Sacramento Food Bank and Family Services (SFBFS), the largest non-profit provider of social services in Sacramento County, this study identified barriers and facilitators to implementing a breast cancer screening intervention in a food distribution setting, assessing the preliminary acceptability and logistical feasibility of the proposed intervention. Qualitative data about food bank distribution events and the clients served was collected over 24 weeks using participant observation with semi-structured fieldnotes and interviews, then analyzed via directed content analysis guided by the well-defined domains and determinants in the Consolidated Framework for Implementation Research (CFIR) and coded using Dedoose software. Fieldnotes were completed for 12 community food distribution events, and 20 stakeholder interviews were conducted with purposefully sampled food bank staff (N=10) and female clients (N=10) who regularly attend events. The results of this qualitative analysis identified barriers and facilitators to implementation in all CFIR domains, describing current workflows for food distribution events and existing health education efforts, capacity, client engagement logistics and modes of delivery, and resources available or needed to support implementation. Prominent CFIR determinants included characteristics of individuals, specifically the innovation recipients’ capability and motivation to receive a breast cancer screening intervention in this context. Participants often pointed out their awareness of important preventative behaviors such as nutrition while also acknowledging barriers such as time constraints, accessibility of breast cancer screening services, and culturally-specific health beliefs and practices. Determinants in the outer setting, inner setting, innovation characteristics, and process that relate to the overall theme of sustainability were identified as potential barriers including financing, the availability of resources, internal and external pressure to change, and the process of engaging with clients while they are at the food distribution event. Facilitators included buy-in from SFBFS leadership and staff, and the benefit of collaborating with reputable local partners. Intervention format should include tailored messaging that is culturally appropriate and empowers individuals to obtain recommended screening. Content of the intervention should provide interactive assistance that facilitates local support for screening eligibility and services. Overall, there was consensus that promoting breast cancer screening in the food distribution setting was beneficial and welcomed by all stakeholders. Citation Format: Charlotte L. Kerber, Julie HT Dang, Daniel J. Pasillas-Pablo, Jocelyn T. Canty, Laura Fejerman. Qualitative analysis of fieldnote and interview data for planning a food bank- based breast cancer screening intervention [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr B048.