BACKGROUND The ultimate treatment goal for ST-segment elevation myocardial infarction (STEMI) is rapid reperfusion via primary percutaneous intervention (PCI). North Carolina has adopted a statewide STEMI referral strategy that advises paramedics to bypass local hospitals and transport STEMI patients directly to a PCI-capable hospital, even if a non-PCI-capable hospital is closer. METHODS AND RESULTS We assessed the adherence of emergency medical services to this STEMI protocol, as well as subsequent associations with patient treatment times and outcomes by linking data from the Acute Coronary Treatment and Intervention Outcomes Network Registry(®)-Get With the Guidelines(™) and a statewide emergency medical services data system from June 2008 to September 2010 for all patients with STEMI. Patients were divided into those (1) transported directly to a PCI hospital, thereby bypassing a closer non-PCI hospital and (2) first taken to a closer non-PCI center and later transferred to a PCI hospital. Among 6010 patients with STEMI, 1288 were eligible and included in our study cohort. Of these, 826 (64%) were transported directly to a PCI facility, whereas 462 (36%) were first taken to a non-PCI hospital and later transferred. In a multivariable model, increase in differential driving time and cardiac arrest were associated with a lesser likelihood of being taken directly to a PCI center, whereas a history of PCI was associated with a higher likelihood of being taken directly to a PCI center. Patients sent directly to a PCI center were more likely to have times between first medical contact and PCI within guideline recommendations. CONCLUSIONS We found that patients who were sent directly to a PCI center had significantly shorter time to reperfusion.