Background: Maintenance hemodialysis patients are particularly vulnerable to infection and hospitalization with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Due to immunocompromise and clustering in outpatient dialysis units, the seroprevalence of COVID-19 antibodies in this population is unknown and has significant implications for public health. Little is also known about their risk factors for hospitalization. Methods: Three outpatient maintenance hemodialysis units affiliated with a major teaching hospital in the New York area were studied. We determined rates of SARS-CoV-2 nasopharyngeal real-time reverse transcriptase polymerase chain reaction (RT-PCR) positivity, SARS-CoV-2 IgG seropositivity, hospitalization, and mortality. Results: Of 367 patients, 28.3% had either SARS-CoV-2 seropositivity or PCR positivity. Prevalence across the three units was 6.7%, 32.3%, and 69.6%. Those who were either antibody or PCR positive were significantly younger (65 vs 69 years, p=0.046), and had higher prevalence of black race (43.3% vs 29.7%, p = 0.001) and Hispanic ethnicity (31.7% vs 11.8%, p < 0.001) compared to those who tested negative. Higher positivity rates were also observed among those who took taxis and ambulettes to and from dialysis, relative to those who used personal transportation. Antibodies were detected in all PCR positive patients testing who underwent serologic testing. Of those that were seropositive, 31.8% were asymptomatic. The hospitalization rate based on either antibody or PCR positivity was 34.6%, with a hospital mortality rate of 33.3%. Aside from COPD, no other variables were more prevalent in hospitalized patients. Conclusions: We observed significant differences in rates of COVID-19 infection within three outpatient dialysis units, with universal seroconversion. Among patients with ESRD, rates of asymptomatic infection appear to be high, as do hospitalization and mortality rates.