OBJECTIVES: Personalized treatment for biomarker-specific breast cancer is a reality. However, outcomes research has lagged behind due to lack of data sources capturing testing, results, and drug treatment.  This study uses a new oncology electronic medical record (EMR) database to examine testing, documentation of results, and appropriate treatment among a cohort of women with breast cancer treated in community oncology practices. METHODS: The Truven Health MarketScan® Oncology EMR Database was used to select patients diagnosed with breast cancer between July 1, 2011 and September 30, 2013 who had at least 2 visits and known disease stage.   Biomarker tests and results for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) were observed along with patients’ drug treatment. RESULTS: