Pay-for-performance reimbursement ties hospital payments to standardized quality-of-care metrics. To the authors' knowledge, the impact of pay-for-performance reimbursement models on hospitals caring primarily for uninsured or underinsured patients remains poorly defined. The objective of the current study was to evaluate how standardized quality-of-care metrics vary by a hospital's propensity to care for uninsured or underinsured patients and demonstrate the potential impact that pay-for-performance reimbursement could have on hospitals caring for the underserved. The authors identified 1,703,865 patients with cancer who were diagnosed between 2004 and 2015 and treated at 1344 hospitals. Hospital safety-net burden was defined as the percentage of uninsured or Medicaid patients cared for by that hospital, categorizing hospitals into low-burden, medium-burden, and high-burden hospitals. The authors evaluated the impact of safety-net burden on concordance with 20 standardized quality-of-care measures, adjusting for differences in patient age, sex, stage of disease at diagnosis, and comorbidity. Patients who were treated at high-burden hospitals were more likely to be young, male, Black and/or Hispanic, and to reside in a low-income and low-educated region. High-burden hospitals had lower adherence to 13 of 20 quality measures compared with low-burden hospitals (all P < .05). Among the 350 high-burden hospitals, concordance with quality measures was found to be lowest for those caring for the highest percentage of uninsured or Medicaid patients, minority patients, and less educated patients (all P < .001). Hospitals caring for uninsured or underinsured individuals have decreased quality-of-care measures. Under pay-for-performance reimbursement models, these lower quality-of-care scores could decrease hospital payments, potentially increasing health disparities for at-risk patients with cancer.