Due to improved detection and treatment, survival rates among breast cancer survivors have increased. However, breast cancer survivors may experience cognitive impairment (CI) following treatment, which has been reported by breast cancer survivors up to 10 years after chemotherapy (CT). There is limited evidence on whether stress-reducing interventions improve CI in breast cancer survivors. The primary goal of this application is to establish the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR(BC)) program as an effective treatment for CI in breast cancer survivors. Specifically this study aim to (1) evaluate the extent to which MBSR(BC) compared to the Breast Cancer-Education Support (BCES) program or Usual Care (UC) improves cognitive functioning among breast cancer survivors off treatment; (2) determine if improvements in cognitive functioning achieved from MBSR(BC) are mediated through increased mindfulness and decreased rumination and stress; (3) evaluate genetic variants as moderators of MBSR(BC) on improvements in CI; and (4) determine the impact of MBSR(BC) on healthcare utilization and costs.