Summary: We compared total costs of care in patients aged 18 to 63 years beginning renal replacement therapy for end-stage renal disease (ESRD) with peritoneal dialysis (PD) or hemodialysis (HD) between January 1, 2005 and December 31, 2008 (“study period”). PD patients were matched to HD patients using propensity scoring to control for differences in baseline characteristics between the two groups. Levels of health care utilization and billed charges in the year following dialysis initiation then were compared between the two groups. We identified 139 patients who began dialysis during the study period (PD, n=26; HD, n=113); after matching, the final study sample consisted of 26 PD patients and 26 HD patients. Mean age of study subjects was 55 years, 58 percent were men, and 72 percent were African American. Over the 12 months, mean billed charges were nominally higher in HD patients ($156,464 vs $127,981 for PD patients; p=0.21). In sensitivity analyses in which patients who began dialysis in hospital were included in the study sample, mean billed charges were significantly higher for HD ($188,340 vs 127,981 for PD; p=0.01). Further study is needed to understand the extent to which these findings derive from differences in dialysis modalities versus the characteristics of patients who receive them.