Patients in custody due to arrest or incarceration are a vulnerable population that present a unique ethical and logistical challenge for emergency physicians (EPs). People incarcerated in the United States have a constitutional right to health care. When caring for these patients, EPs must balance their ethical obligations to the patient with security and safety concerns. They should refer to their institutional policy for guidance and their local, state, and federal laws, when applicable. Hospital legal counsel and risk management also can be helpful resources. EPs should communicate early and openly with law enforcement personnel to ensure security and emergency department staff safety is maintained while meeting the patient's medical needs. Physicians should consider the least restrictive restraints necessary to ensure security while allowing for medical evaluation and treatment. They should also protect patient privacy as much as possible within departmental constraints, promote the patient's autonomous medical decision‐making, and be mindful of ways that medical information could interact with the legal system.