ABSTRACT Background and Objectives Among patient with early‐stage breast cancer, breast conservation surgery (BCS) is the most performed surgery, utilized in approximately two‐thirds of patients. While 5‐year overall‐survival rates are strong—typically above 90%—additional re‐excisions can occur in up to 25% of patients who undergo index BCS and some patients will require subsequent surgery for new breast cancer or recurrences. As such, these additional procedures can complicate patients’ pathway to survivorship, negatively impact quality of life, and lead to excess healthcare costs. Methods This retrospective cohort study used linked claims and an electronic healthcare record database to (1) characterize patients at higher risk for additional breast oncologic surgery (aBOS) following BCS, and (2) quantify the long‐term financial impact of aBOS after BCS. In total, 87,190 patients with breast cancer, who had an index BCS between January 1, 2012, to March 31, 2023, were followed for up to 5‐years post‐operatively. Patients with and without aBOS were analyzed, comparing demographics, tumor characteristics, healthcare utilization, and per‐person‐per‐month (PPPM) costs. Results Twenty‐three percent ( n = 20,212) of patients underwent aBOS. These patients were younger, had higher tumor grades and larger tumor sizes, and incurred greater healthcare costs compared to patients who did not undergo a secondary surgery. Conclusion This study highlights significant factors influencing BCS outcomes and healthcare utilization, underscoring the need for tailored therapeutic strategies for patients with breast cancer.