Objective and Background: Minimally invasive breast biopsy (MIBB) rates remain well below guideline recommendations of more than 90% and vary across geographic areas. Our aim was to determine the variation in use attributable to the surgeon and facility and determine the patient, surgeon, and facility characteristics associated with the use of MIBB. Methods: We used 100% Texas Medicare claims data (2000-2008) to identify women older than 66 years with a breast biopsy (open or minimally invasive) and subsequent breast cancer diagnosis/operation within 1 year. The percentage of patients undergoing MIBB as the first diagnostic modality was estimated for each surgeon and facility. Three-level hierarchical generalized linear models (patients clustered within surgeons within facilities) were used to evaluate variation in MIBB use. Results: A total of 22,711 patients underwent a breast cancer operation by 1226 surgeons at 525 facilities. MIBB was the initial diagnostic modality in 62.4% of cases. Only 7.0% of facilities and 12.9% of surgeons used MIBB for more than 90% of patients. In 3-level models adjusted for patient characteristics, the percentage of patients who received MIBB ranged from 7.5% to 96.0% across facilities (mean = 50.1%, median = 49.2%) and from 8.0% to 87.0% across surgeons (mean = 50.3%, median = 50.9%). The variance in MIBB use was attributable to facility (8.8%) and surgeon (15.4%) characteristics. Lower surgeon and facility volume, longer surgeon years in practice, and smaller facility bed size were associated with lower rates of MIBB use. Conclusions: Identification of surgeon and facility characteristics associated with low use of MIBB provides potential targets for interventions to improve MIBB rates and decrease variation in use.