Few data exist related to the impact of breast cancer on work absenteeism and short-term disability. This retrospective study estimated the extent and costs of breast cancer-associated production loss using a large medical and pharmacy claims database from a US commercially insured population between January 2003 and December 2007. Women aged ≥ 18 years with ≥ 2 breast cancer diagnoses within 90 days were selected. Controls were matched to cases based on index date (first breast cancer diagnosis), age, region, employer, and health insurance type. Outcomes were days absent from work and days with short-term disability. Costs were estimated using daily wage rates. 856 and 2,668 patients were selected for absenteeism and short-term disability, respectively, with a mean age of 49 and 50 years. Average number of absenteeism days was 35 and 21, and short-term disability days were 51 and 5, for cases and controls, respectively, within the post-index year (both P < 0.001). Adjusted incremental costs for absenteeism and short-term disability were $1,911 and $6,157 (P < 0.001), respectively, per breast cancer patient per year. This study suggests that breast cancer is associated with work-related productivity loss within the first year of diagnosis that may be a substantial cost to employers.