[1] She was nominated by President George W. Bush on July 17, and confirmed by the United States Senate on November 2, 2001.

On February 1, 2007, the Senate confirmed Michael J. Astrue to replace Mrs. Barnhart for a six-year term beginning on January 20, 2007.

The SSI program paid monthly benefits to more than 7 million Americans who have little or no resources and who are aged, blind or disabled.

During her career, Mrs. Barnhart served as Senator William V. Roth, Jr.’s legislative assistant (1977–1981) and as his campaign manager (1988, 1994 and 2000),[2] she was political director of the National Republican Senatorial Committee (NRSC; 1995–1996) and managed her own political and public policy consulting firm.

She has been an adjunct lecturer at the John F. Kennedy School of Government, Harvard University since 2008 where she teaches a course on designing social security programs.