Background: In patients ≥70 with early stage (pT1, c/p N0), hormone-receptor positive/ HER2 negative breast cancer, there is an opportunity to reduce adjuvant treatment burden through short-course radiotherapy (RT) approaches and/or endocrine therapy (ET) monotherapy. However, practices may vary in approach to treatment, necessitating differences in approach to interventions designed to tailor decision-making. Methods: Site needs assessment and semi-structured stakeholder interviews at 6 Minority Underserved NCORP sites was conducted, including 3 radiation oncologists (RO), 2 medical oncologists (MO), 1 research coordinator, and 2 breast surgeons (BS). Participant responses were manually recorded and used to construct structural and workflow maps for the possible patient care pathways across the 6 sites. Baseline information on ET and RT use was collected. A planned multi-level intervention that includes patient questionnaires (including a mortality risk calculator) to inform tailored decision-making, and education on guideline-concordant, lower burden options was introduced and dominant themes for barriers and facilitators of the intervention were abstracted. Results: Patients followed multiple pathways and received care at more than one site. The 6 sites span urban, suburban, and rural areas with variable presence of provider types (RO, MO, BS), research support, and RT technology. At baseline, patient reported data, geriatric assessments, mortality risk calculators, and decision aid tools were not routinely used. About 85% of eligible patients receive both ET and moderately hypofractionated whole breast RT; the only commonly used form of partial breast RT is intra-operative. Themes were physician acceptability of the intervention, multidisciplinary care, and physician willingness to offer lower burden treatment options. Physician acceptability subthemes included high baseline guideline knowledge, interest in mortality risk calculator use, need for support to interpret and incorporate patient questionnaire data, and variable physician research engagement. Multidisciplinary care facilitators were multi-campus tumor boards and strong research support staff; barriers were variable insurance across providers and surgeon-driven care plan expectations. Lower burden care subthemes included support for ET for almost all patients; barriers to RT omission were concern about ET non-adherence and to short-course RT were lack of data and toxicity concerns in patients with larger body habitus/resultant RT dose inhomogeneity. Conclusions: Results demonstrated multiple barriers and facilitators of interventions targeting lower burden treatment options for low-risk early-stage breast cancer and identified physician education about interpretation/use of patient-reported data and mortality risk assessments as key to successful study design.