The United States Tax Court Building is a courthouse located at 400 Second Street, Northwest, Washington, D.C., in the Judiciary Square neighborhood.

In an attempt to improve federal buildings, the committee recommended architecture that would convey the "dignity, enterprise, vigor, and stability of the American Government".

In 1962, Secretary of the Treasury Douglas Dillon appealed to the U.S. General Services Administration (GSA) to incorporate funds for the design of a new building in its upcoming budget.

In 1966, GSA approved Lundy's concept for a building with strong end masses, a central cantilevered courtroom block, and a landscaped plaza.

Despite enthusiastic support for the project, the Vietnam War triggered funding cuts that delayed construction until 1972, when GSA secured a site and held a groundbreaking ceremony.

Hailing the design in 1967, New York Times architectural critic Ada Louise Huxtable described the plans for the U.S. Tax Court Building as "a progressive, sensitive, contemporary solution fully responsive to Washington's classical tradition and yet fully part of the mid-20th century - a period of exceptional vigor and beauty in the history of structure and design".

The building is clad in flame-treated Royal Pearl granite from Georgia and bronze-tinted, heat-absorbing, glare-reducing glass with slim bronze-anodized aluminum mullions.

Compression and post-tensioned bridges, steel cables hidden within the building's walls, and six slender columns together support the imposing 4,000-ton cantilevered courtroom block, which projects over the entrance.

Lundy designed the plaza, located on the Second Street side of the building, with a central reflecting pool flanked by landscaped areas.