© The Author(s) 2020. Social inequity can have broad health impacts. The purpose of this study was to examine the effects of low income and nonadherence to health supervision visits on emergency room (ER) utilization in Eastern Brooklyn, New York. This study surveyed parents/guardians of children who received routine medical care at Brookdale ambulatory clinics from June 2017 to February 2018. Participants were asked to fill out a questionnaire on social demographics, food insecurity, and relocation. Electronic medical records (EMRs) were reviewed to retrieve numbers of missing health supervision and ER visit in past 12 months. Comorbidity was identified through EMR by International Classification of Diseases. Logistic regression analyses were used to examine the effects of nonadherence to health supervision visits on ER utilization when controlling for demographics, food insecurity, recent moving, and comorbidity. Among 268 participants, 56.0% reported their household income was less than $20,000 annually, 39.6% missed at least 1 health supervision visit, and 31.7% had at least 1 ER visit within the past 12 months. Younger age (adjusted odds ratio [aOR] = 0.92, 95% confidence interval [CI] = 0.86-0.97, P <.01), household income less than $20,000 (aOR = 1.86, 95% CI = 1.02-3.39), preexisting comorbidity (aOR = 2.36, 95% CI = 1.26-4.42), and nonadherence to health supervision visits (aOR = 5.83, 95% CI = 3.21-10.56) were associated with increased ER utilization. Nonadherence to health supervision visits is an independent risk factor and potentially modifiable. Evaluation and remediation should be pursued as a means of improving health outcomes of children in vulnerable circumstances.