Sudden hospital closures displace patients from usual sources of care and force them to access facilities that lack their prior medical records. For patients with complex needs and for nearby hospitals already strained by high volume, disaster-related hospital closures induce a public health emergency. Our objective was to analyze responses of patients from public versus private emergency departments after closure of their usual hospital after Hurricane Sandy. Using a statewide database of emergency visits, we followed patients with an established pattern of accessing 1 of 2 hospitals that closed after Hurricane Sandy: Bellevue Hospital Center and NYU Langone Medical Center. We determined how these patients redistributed for emergency care after the storm. We found that proximity strongly predicted patient redistribution to nearby open hospitals. However, for patients from the closed public hospital, this redistribution was also influenced by hospital ownership, because patients redistributed to other public hospitals at rates higher than expected by proximity alone. This differential response to hospital closures demonstrates significant differences in how public and private patients respond to changes in health care access during disasters. Public health response must consider these differences to meet the needs of all patients affected by disasters and other public health emergencies.