To describe current practice regarding the use of physician extenders (PEs) and the "fast track" (FT) concept in United States emergency departments (EDs), a telephone survey of 250 US health care facilities offering emergency services was conducted. Of the EDs surveyed, 21.6% were using PEs at the time of the survey, and of those not using PEs, 23.5% intended to do so within the next 2 years. Those using PEs had been using them for a mean duration of 3.5 years (the mode was 2 years). The mean number of hours of PE coverage was 11.4 hours on weekdays and 11.5 hours on weekends (the mode was 12 hours both on weekdays and weekends). In general, the use of PEs increased with increasing hospital size and ED census, in more urban settings, in teaching facilities, and in the Northeast region of the country. Thirty percent of EDs surveyed had FT, and of those that did not have FT at the time of the survey, 32.8% intended to institute FT within 2 years. Of those that had FT, the mean number of years in use was 2.4 (the mode was 2). The use of FT increased with increasing hospital size and ED census, in teaching hospitals, and in the Northeast region. FT was most common in the suburban setting. The mean estimated percentage of ED patients going through FT was 30.1%. The mean number of hours per day of FT operation was 13.4 hours on weekdays and 13.7 hours on weekends (the mode was 12 hours/day both on weekdays and weekends). Of hospitals using PEs in the ED, 56.0% had FT; of hospitals without PEs in the ED, 23.5% had FT.