Cardiac rehabilitation (CR) use is lower for racial and ethnic minorities than White patients. The purpose of this study was to identify factors that drive this disparity at the system, provider, and patient levels. A mixed methods study combined descriptive analysis of 2007 Medicare claims data and thematic analysis of 19 clinician interviews, 8 minority patient focus groups and 8 one-on-one interviews with minority heart patients across three communities. The disparity between White and non-White CR use ranged from 7 to 11 percentage points among study sites (p