The Twenty-five Year Award is an architecture prize awarded each year by the American Institute of Architects (AIA) to "a building that has set a precedent for the last 25 to 35 years and continues to set standards of excellence for its architectural design and significance" and which was designed by an architect licensed in the United States. The Twenty-five Year Award was first presented in 1969, and has been handed out every year from 1971 onward, with the exception of 2018. In 2023, the prize was awarded to the Guggenheim Museum Bilbao in Bilbao, Spain by Gehry Partners.

Skidmore, Owings & Merrill LLP (SOM) is an American architectural, urban planning and engineering firm. It was founded in 1936 by Louis Skidmore and Nathaniel Owings in Chicago. In 1939, they were joined by engineer John Merrill. The firm opened its second office, in New York City, in 1937 and has since expanded, with additional offices in San Francisco, Los Angeles, Washington, D.C., London, Melbourne, Hong Kong, Shanghai, Seattle, and Dubai.