Breast cancer screening decision aids that help women understand their risk for cancer and available screening options can improve the quality of decision-making for women in their 40s, but existing decision aids do not address the needs of women with limited health literacy. We conducted a Delphi panel among breast cancer screening and decision science experts to determine content for a breast cancer screening decision aid for women ages 40-54 who have limited health literacy. Experts were those with an advanced degree (MD, PhD), at least 3 years of experience, and content expertise in breast cancer screening, health literacy, or decision aid design. Experts were invited via email to participate in an online Delphi panel, which aimed to establish consensus on decision aid content, guided by the International Patient Decision Aid Standards. Experts rated the importance of each item on a scale from 1 (not important) to 9 (very important), as well as how strong they felt the evidence was to support each. Open-ended responses explaining ratings were gathered, and in Round 1 experts were asked to nominate new items for inclusion. Following RAND methods, the 30th - 70th percentile range, central point, and asymmetry index were calculated for each item. From these values, a disagreement index was determined, and if the value was >1, indicating disagreement, the item was moved to the next round. Otherwise, consensus was established, and the item was omitted from future rounds. Between rounds, experts received a summary of their rating for each item relative to others, along with a summary of the open-ended explanations. The process was repeated for Rounds 2 and 3. 15 experts were invited, 9 agreed and 8 completed Round 1. All eight participants were female, with an average age of 53. Seven were white and 2 Asian. Five held medical doctorate degrees, 3 had PhDs. Seven experts completed all 3 rounds. Round 1 included 55 items, 30 of which obtained consensus (disagreement index < 1). 29 items were reviewed in Round 2 (25 from Round 1, plus 4 newly nominated items), 15 of which obtained consensus, leaving a final round of 14 items. In Round 3, 1 item achieved consensus, 4 items converged around uncertainty, and 9 did not reach consensus. Experts disagreed or were uncertain on the importance of including breast cancer risk factors and whether a description of the multiple screening modalities available should be included. Explanations for these items described balancing an ethical imperative to provide information and avoid paternalism while limiting information extraneous to the decision. While guidelines suggest that the age of initiating mammography and modalities used should involve an assessment of risk of developing breast cancer, experts did not agree about the inclusion of risk factor or modality information in a breast cancer screening decision aid for women with limited health literacy. Balancing detail with simplicity remains a challenge in determining content for decision support tools that seek to include a range of literacy levels. Citation Format: Christine M. Gunn, Tracy A. Battaglia, Michael K. Paasche-Orlow, Mara Schonberg, Ariel Maschke, Nancy R. Kressin. Using a Delphi panel to establish content for a breast cancer screening decision aid inclusive of women with limited health literacy [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-017.