On October 31, 1912, Meyer signed Navy General Order No. 233, which renamed the school the Postgraduate Department of the United States Naval Academy. The order established courses of study in ordnance and gunnery, electrical engineering, radio telegraphy, naval construction, and civil engineering as well as continuing the original program in marine engineering.

During World War II, Fleet Admiral Ernest King, chief of naval operations and commander-in-chief of both the Atlantic and Pacific fleets, established a commission to review the role of graduate education in the Navy. In 1945, Congress passed legislation to make the school a fully-accredited, degree-granting graduate institution. Two years later, Congress adopted legislation authorizing the purchase of an independent campus for the school.
A post-war review team, which had examined 25 sites nationwide, had recommended the old Hotel Del Monte in Monterey as a new home for the Postgraduate School. Negotiations with the Del Monte Properties Company led to the purchase of the hotel and 627 acres (2.5 km²) of surrounding land for $2.13 million.

In December 1951, the Postgraduate School moved across the nation, establishing its current campus in Monterey.

Today, the school has over 40 programs of study including engineering, physical sciences, space science, computer science, business, international relations, and other disciplines, all with an emphasis on military applications. It is home to the Center for Information Systems Security Studies and Research (CISR) and the Center for Homeland Defense and Security (CHDS). CISR is America's foremost center for defense-related research and education in Information Assurance (IA), Inherently Trustworthy Systems (ITC), and defensive information warfare; and CHDS provides the first homeland security master’s degree in the United States.

The Naval Postgraduate School is a graduate school operated by the United States Navy. Located in Monterey, California, it grants primarily master's degrees plus some doctoral degrees to its students, who are mostly active duty officers from U.S. and foreign military services.

Its campus was once a resort hotel; some of its buildings and its cactus garden date from that time.