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NLM® Reading Rooms and Services - Hours

Reading Rooms Hours | Tours & Other Information

Main and History of Medicine Reading Room Hours

Monday - Friday, 8:30 a.m. - 5:00 p.m.

The last request for materials is sent to the closed stacks one hour before closing.

The Reading Rooms are closed weekends and Federal holidays. For a list of holidays, check Holiday Closings for NLM Reading Rooms at For special hours and emergency closings, call 1-888-FINDNLM (1-888-346-3656) or 301-594-5983. The Reading Rooms close whenever the U.S. Office of Personnel Management (OPM) determines that federal government offices in the metropolitan Washington, DC area should close for weather, emergencies, or events. You may check the Office of Personnel Management for OPM Current Status at

Tours & Other Information

NLM tours start at 1:30 p.m. Monday - Friday in the Visitors Center (Lobby of Building 38A, Lister Hill Center). To arrange a group tour, please call 301-496-6308.

NIH Visitors and Security information is at

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