Objective: An admission to a medical or psychiatric inpatient unit is a difficult time during a Transitional Age Youth (TAY)’s life. While some patients recognize the need for their admission, severely ill patients lack insight into their illnessand require involuntary hospitalization, which may impactthe patient’s quality of care, patient-doctor relationship and raise legal and ethical questions to patient’s autonomy, capacity, and their wishes. Methods: Describe the legal and ethical challenges of TAY with serious mental illness and multiple physical illnesses; illustrated by a clinical case. Results: TAYis affected by legal issues involved with treatment in this population, including a patient’s right to refuse treatment, involuntary commitment versus court-ordered treatment, advance directives, health care proxies, and confidentiality. Conclusions: It is critical to recognize the ethical and legal issues encountered by TAY with serious mental illness. Understanding these matters will improvethe provider’s care and enhance their ability to advocate for patients’ rights.