Mason Barr, a retired federal government executive who lived here through parts of four decades, died of emphysema Sept. 12 at a hospital in Sanford, Maine. He was 76.

Mr. Barr, was born in Youngstown, Ohio, and was a 1922 graduate of the University of Michigan. He came to Washington in 1934, and worked in the following years in the National Recovery Administration, the Resettlement Administration, and the Farm Security Administration. He became director of the management division of the FSA agency in 1940, concentrating on housing and farm projects for migrant agricultural laborers.

In 1943, Mr. Barr moved to the War Food Administration and the following year was named assistant to the governor of Puerto Rico, specializing in housing and community development programs.

After World War II, Mr. Barr was named chief of the Carribbean division of the Department of the Interior.

Mr. Barr left the federal government in 1954 for employment in the paper industry in Ohio, but returned in 1962 as director of housing development for the Bureau of Indian Affairs. He held this position until his retirement in 1967.

In Washington, the Barr family lived primarily in Falls Church and Bethesda.

Mr. Barr is survived by his wife, the former Mary Archbold Walton, of the home in Limerick, Maine; two daughters, Mary Wagner and Frances Noland, and a son, Dr. Mason Barr Jr., all of Ann Arbor, Mich.; a brother, J. Henderson Barr of Cornish, Maine and a sister, Laura Lougee of Parsonsfield, Maine.