The Oversight, Protection, and Enforcement Notification Act, or OPEN Act, seeks to improve transparency, preserve civil rights, and enhance accountability within immigration enforcement operations and detention facilities. It grants Members of Congress unrestricted and unannounced access to all immigration detention facilities, including the ability to speak privately with detainees and observe conditions. This access also extends to congressional staff and subject matter experts, with strict prohibitions against delaying or denying entry and consequences for repeated non-compliance. The bill mandates that the Department of Homeland Security (DHS) track and publicly report allegations and incidents of excessive force, unauthorized conduct, sexual assault, and mistaken detentions by immigration enforcement personnel. It requires all detention facilities to maintain confidential and accessible grievance processes for detainees, available in multiple languages. Furthermore, any officer, employee, or contractor found to have used excessive force must be immediately removed from duties involving detainee supervision or transport. The legislation establishes several detainee rights , including notification of immediate family within five hours of detention, guaranteed access to a phone call, and timely access to legal counsel and faith leaders. It also ensures comprehensive medical and mental health services, including access to VA care for eligible individuals, and outlines procedures for family members to provide prescription medications and medical devices. Strict standards are imposed on detainee transfers, requiring notice to legal counsel and family, written justification, medical summaries, and adherence to specific transport protocols like seatbelts, regular bathroom breaks, and continuous monitoring. Additionally, the bill places limitations on converting existing buildings into immigration detention centers, requiring full compliance with federal detention and safety standards, guaranteed detainee access to legal and family contacts, and independent inspections. Crucially, it mandates that immigration enforcement officers and agents obtain judicially enforceable warrants for arrests or detentions, prohibiting the use of administrative warrants for forced entry into private residences. The bill also reconstitutes the Office for Civil Rights and Civil Liberties within DHS with an independent reporting structure to investigate violations.