The reasons for the increased annual incidence of end-stage renal disease (ESRD) in blacks compared with whites are unclear, but may include lack of access to treatment of the causative disease, which likely relates closely to socioeconomic status (SES). End-stage renal disease rates for diabetic glomerulosclerosis, hypertensive nephrosclerosis, and glomerulonephritis were determined in the 9,390 black and white New York State residents who began treatment within the Medicare program between 1982 and 1988. The relationship between the incidence of ESRD, age, and SES, as measured by the race-specific median family income in the patient's zip code, was estimated using a series of logistic-regression models for 12 populations: three causes of renal failure by two races by two sexes. For whites, incidence rates of diabetic glomerulosclerosis and hypertensive nephrosclerosis were significantly negatively associated with declining SES for the 45 to 65 year and 25 to 55 year age groups, respectively. In contrast, there was no relationship between the incidence of these diseases and SES in blacks. For glomerulonephritis, effects of SES were minor for both races. Better access to treatment of diabetes and hypertension might well decrease the annual incidence of ESRD due to diabetic glomerulosclerosis and hypertensive nephrosclerosis in whites. If the SES measures used for blacks are adequate, predisposition to progressive renal damage in response to renal injury or environmental factors other than SES are stronger risk factors for ESRD than SES.