Background: Although healthcare leaders in the US support an active role for primary care (PC) in the care of patients with a history of breast cancer, the nature of this role remains unclear. Methods: We invited 40 innovators in breast cancer survivorship care to participate in a 4-round online Delphi panel to identify strategies for defining and fostering PC’s role in breast cancer survivorship. Innovators included primary care physicians, oncologists, researchers and policy makers from government and professional organizations participating in survivorship care programs in the US. Round 1 elicited strategies for improving PC’s role in survivorship care. To reduce the number of strategies and participant burden in subsequent rounds, Round 2 asked panelists to prioritize the top 10 strategies they perceived to be most crucial for implementation. Round 3 asked panelists to assess the importance and feasibility of the previously ranked strategies on a 1-9 scale. In the final round, panelists were asked to review the group results (medians, IQRs) and reevaluate the importance and feasibility of each strategy in an effort to reach consensus. The RAND/UCLA Appropriateness Method determined the final group rating for each strategy. Results: Of the 40 invited, 23 responded to the email and were included. In Round 1, panelists (n = 23) collectively identified 31 unique strategies to support survivorship care. In Round 2, two of the 31 strategies were unranked by any of the 23 panelists and were eliminated from subsequent rounds. In Round 3, panelists’ (n = 15) evaluated importance and feasibility and revealed three strategies to be most important (scored 9) but with uncertain feasibility (scored 5 or 6). All three strategies emphasized the need to foster connections between primary care and oncology: (1) define clear roles and responsibilities for oncology and primary care, (2) train oncologists about how primary care can address survivorship care needs, (3) create clear pathways for communicating/sharing information with oncology. In Round 4, panelists (n = 20) confirmed the most important strategies and evaluated five strategies as both important and feasible, targeting a range of approaches including EHR-based strategies (e.g., enable screening reminders, monitoring alerts, automated messaging within EHRs in PC), patient education (e.g., educate patients on survivorship), and resource development/distribution (e.g., distribute accessible clinician reference guides detailing common breast cancer drugs and effects). Conclusions: Although innovators identified important and feasible strategic initiatives at various levels of implementation, they agreed that the most important strategies were those that clarified roles and improved communication between oncology and PC but these were not feasible, indicating the need to invest resources to build capacity between PC and oncology.