Commissioned a lieutenant, DeMao commanded a landing craft during the Normandy invasion, making nine dangerous trips to the beach to deliver soldiers to the shore.

[1] Since most professional football players received only minimal pay in the 1950s, DeMao took up employment in the off-season with liquor distributor Milton S. Kronheim & Co. After retiring from football in 1954, DeMao remained with the company, rising to vice president of sales.

He was active in Special Olympics and the Boys & Girls Clubs of America, assisted with the St. John's College High School football team, and coached football teams with the Boys Club of America and the Catholic Youth Organization.

He also raised funds for the Muscular Dystrophy Association, the National Multiple Sclerosis Society, and the Darrell Green Youth Life Foundation.

Al DeMao died of pneumonia at Baltimore Washington Medical Center in Glen Burnie, Maryland, on February 1, 2008.