Racial/ethnic disparities in breast cancer survival are well documented, but the influence of health care institutions is unclear. We therefore examined the effect of hospital characteristics on survival. Harmonized data pooled from 5 case-control and prospective cohort studies within the California Breast Cancer Survivorship Consortium were linked to the California Cancer Registry and the California Neighborhoods Data System. The study included 9,701 patients with breast cancer who were diagnosed between 1993 and 2007. First reporting hospitals were classified by hospital type-National Cancer Institute (NCI) -designated cancer center, American College of Surgeons (ACS) Cancer Program, other-and hospital composition of the neighborhood socioeconomic status and race/ethnicity of patients with cancer. Multivariable Cox proportional hazards models adjusted for clinical and patient-level prognostic factors were used to examine the influence of hospital characteristics on survival. Fewer than one half of women received their initial care at an NCI-designated cancer center (5%) or ACS program (38%) hospital. Receipt of initial care in ACS program hospitals varied by race/ethnicity-highest among non-Latina White patients (45%), and lowest among African Americans (21%). African-American women had superior breast cancer survival when receiving initial care in ACS hospitals versus other hospitals (non-ACS program and non-NCI-designated cancer center; hazard ratio, 0.67; 95% CI, 0.55 to 0.83). Other hospital characteristics were not associated with survival. African American women may benefit significantly from breast cancer care in ACS program hospitals; however, most did not receive initial care at such facilities. Future research should identify the aspects of ACS program hospitals that are associated with higher survival and evaluate strategies by which to enhance access to and use of high-quality hospitals, particularly among African American women.