This article analyzes the effectiveness of designated trauma centers in Florida concerning reduction in the mortality risk of severely injured trauma victims. A bivariate probit model is used to compute the differential impact of two alternative acute care treatment sites. The alternative sites are defined as (1) a nontrauma center (NC) or (2) a designated trauma center (DTC). An instrumental-variables method was used to adjust for prehospital selection bias in addition to the influence of age, gender, race, risk of mortality, and type of injury. Treatment at a DTC was associated with a reduction of 0.13 in the probability of mortality.