This report examines the efforts by three federal organizations--the Department of Veterans Affairs, the Department of Transportation, and the National Aeronautics and Space Administration--to change the behavior of those within the organization to move in greater concert toward the achievement of organizational goals. The three initiatives--One VA, ONE DOT, and One NASA--were each unique and faced distinct challenges. The report examines what it means for a federal organization to become "one," the hurdles each agency faced, and which strategies appear to work well.