Objectives: Access to care and poverty have been associated with a higher risk of breast cancer, but their impact on breast cancer death has not been fully evaluated. We hypothesized that analysis of data from a large database would further elucidate the association between socioeconomic status and breast cancer mortality. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify cases of invasive ductal carcinoma diagnosed between 2006-2011, as well as data reflecting the presence or absence of a breast cancer death within five years. Two age groups, 40-64 year old women, and 65+ year old women, were analyzed. From the American Community Survey were acquired annual county level hospital rates, ambulatory care facility rates, nursing/residential care facility rates, rural business rates, population densities, and counts of women in the age groups of interest. Results: With respect to poverty rates, incidence based mortality rates for 40-64 year old women were 13% (99% CI 3%, 25%) higher for counties in the third quartile and 19% (7%, 35%) higher for counties in the fourth quartile (p < 0.01) than for counties in the first quartile; counties in the second quartile did not show higher incidence mortality rates (p > 0.01). Mortality rates for 65+ year old women did not differ among poverty rate quartiles (p > 0.01 for each assessment). A 50% increase in hospitals per 100,000 persons was associated with 8% (5%, 11%) and 5% (1%, 8%) increases in mortality rates for 40-64 y and 65+ y women, respectively, likely reflecting better ascertainment of causes of death at hospitals. Impacts of differences in other rates and population density were not detected (p > 0.01 for each analysis). Conclusion: Counties with higher poverty rates have increased breast cancer mortality rates for 40-64 y women, but not for 65+ y women. Universal coverage associated with Medicare is associated with the absence of an apparent effect of poverty upon breast cancer mortality.