25 Background: Women with diabetes are at an increased risk of developing breast cancer, present with later stage disease, and experience higher breast cancer-specific mortality compared to nondiabetic women. Thus, it is imperative that diabetic women undergo routine screening mammography. Previous studies have shown conflicting results with smaller studies showing lower screening mammography rates among diabetics while a study using national self-report data showed that diabetic women were equally likely to be screened compared to nondiabetic women. Given the conflicting data and limitations of previous studies, we aimed to study receipt of mammography in diabetic women using a nationally representative administrative claims database. Methods: This was a retrospective study using a nationally representative administrative claims database from January 1, 2010, through December 31, 2012. We compared rates of receipt of mammography within a 2-year time frame in diabetic and nondiabetic women ages 40 to 64. We used Healthcare Effectiveness Data and Information Set (HEDIS) logic to define women with diabetes. We used CPT and ICD-9 codes to identify mammogram services received. We calculated odds ratios with 95% confidence intervals to compare mammogram rates among diabetics compared to nondiabetics. Results: 1,723,674 nondiabetic women and 133,973 diabetic women were identified. Among women ages 40 to 49, diabetic women had significantly decreased mammography rates compared to nondiabetic women (OR 0.84; 95% CI 0.83, 0.85). Rates were also lower in diabetic women ages 50 to 64 (OR 0.88; 95% CI 0.88, 0.91). Despite lower mammography rates among diabetics, diabetic women had 1.78 times more visits than nondiabetic women. Conclusions: Women with diabetes are less likely to undergo routine screening mammography than women without diabetes, despite having more encounters with health care providers. This study serves as a reminder to provide timely preventive health services to all patients regardless of medical comorbidities.