regional differences in recipient waitlist time and pre and posttransplant mortality after the 2006 united network for organ sharing policy changes in the donor heart allocation algorithm objectives this study examined the impact of the united network for organ sharing unos policy changes for regional differences in waitlist time and mortality before and after heart transplantationbackground the 2006 unos thoracic organ allocation policy change was implemented to allow for greater regional sharing of organs for heart transplantationmethods we analyzed 36789 patients who were listed for heart transplantation from january 1999 through april 2012 these patients were separated into 2 eras centered on the july 12 2006 unos policy change pre and posttransplantation characteristics were compared by unos regionsresults waitlist mortality decreased nationally up to 180 days 133 vs 79 after the unos policy change p 0001 and within each region similarly 2year posttransplant mortality decreased nationally 2year mortality 173 vs 146 p 0001 as well as regionally waitlist time for unos status 1a and 1b candidates increased nationally 178 days on average p 0001 with variability between the regions the greatest increases were in region 9 592day increase p 0001 and region 4 412day increase p 0001 although the use of mechanical circulatory support increased nearly 23fold nationally in era 2 significant differences were present on a regional basis in regions 6 7 and 10 nearly 40 of those transplanted required left ventricular assist device bridging whereas only 196 223 and 155 required a left ventricular assist device in regions 3 4 and 5 respectivelyconclusions the 2006 unos policy change has resulted in significant regional heterogeneity with respect to waitlist time and reliance on mechanical circulatory support as a bridge to transplantation although overall both waitlist mortality and posttransplant survival are improved