The size of the prevalent ESRD population in the United States increased dramatically during the 1990s, from 196,000 in 1991 to 382,000 in 2000. Incidence also increased considerably during the same period, from 53,000 to 93,000 per year. If previous trends in ESRD incidence and prevalence continue, then current levels of health care resources that are devoted to the care of these patients will eventually be unable to meet the demand. This study discusses a Markov model developed to predict ESRD incidence, prevalence, and mortality to the year 2015 and incorporating expected changes in age/race distributions, diabetes prevalence, ESRD incidence, and probability of death. The model predicted that by 2015 there will be 136,166 incident ESRD patients per year (lower/upper limits 110,989 to 164,550), 712,290 prevalent patients (595,046 to 842,761), and 107,760 ESRD deaths annually (96,068 to 118,220). Incidence and prevalence counts are expected to increase by 44 and 85%, respectively, from 2000 to 2015 and incidence and prevalence rates per million population by 32 and 70%, respectively. The financial and human resources that will be needed to care for these patients in 2015 will be considerably greater than in 2005.