In the United States, with the exception of skin cancer, breast cancer accounts for the greatest number of incident cancer diagnoses in women and is the second most frequent cause of female cancer-related deaths. Compared to the general U.S. population, female military members have been estimated to have higher breast cancer rates. Between 2000 and 2012, 1,092 female active component members were diagnosed with breast cancer; 244 (22.3%) of these cases were ductal carcinoma in situ (DCIS). The overall crude incidence rate of breast cancer was 40.6 per 100,000 person-years (p-yrs); the lowest annual incidence rate was 28.6 per 100,000 p-yrs in 2006, and the highest annual incidence rate was 53.6 per 100,000 p-yrs in 2001. Over the surveillance period, the crude incidence rate of DCIS cases was 9.1 per 100,000 p-yrs; for other (invasive) breast cancer diagnoses the rate was 31.5 per 100,000. Potential differences in breast cancer risk factors between military and civilian women are discussed.