Medicare's End-Stage Renal Disease (ESRD) Program makes renal replacement services accessible for the majority of Americans with renal failure. National data from Medicare demonstrate complex and variable patterns of use of renal replacement services among US racial and ethnic groups. The black population has consistently suffered from a greater than 3.5-fold higher rate of treated ESRD than has the white population. The rates of hypertensive, diabetic, and glomerulopathic ESRD are all substantially greater in blacks than in whites, and hypertension has accounted for a far greater proportion of ESRD in blacks than any other diagnosis. There is a paucity of national data on the occurrence of ESRD in Hispanic Americans. However, data from Texas strongly suggest that the incidence rate of treated ESRD is much higher in Mexican Americans than in non-Hispanic whites. Higher rates are apparent for each of the three most important causes of ESRD: hypertension, diabetes, and glomerulonephritis. Native Americans experience ESRD at a rate intermediate between those of whites and blacks, but their rate of diabetic ESRD is higher than in either blacks or whites. However, considerable diversity exists among Native American tribal groups. Significant barriers to the acquisition of preventive care have been identified, especially for blacks. While these barriers to preventive care are accompanied by a significantly impaired health status of the black American population, a specific causal relationship between impaired access to care for blacks and their predisposition to ESRD has not been established.