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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.

If the Office of Personnel Management (OPM) status is "delayed arrival," the library opens at 10:30 a.m. If the status is "early dismissal," the library closes at 3:00 p.m. For other conditions, check the 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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