Over 55 percent of the nearly 130 million taxpayers in tax year 2001 used a paid tax preparer. However, using a preparer may not assure that taxpayers pay the least amount due. Last year, GAO estimated that as many as 2 million taxpayers overpaid their 1998 taxes by $945 million because they failed to itemize deductions and half of these used preparers. GAO was asked to (1) obtain the views of taxpayers about paid preparers and examples of preparer performance including any problems and (2) describe the Internal Revenue Service's (IRS's) oversight of problem preparers; the challenges facing IRS in dealing with problem preparers, especially the Office of Professional Responsibility; and the efforts to address those challenges. To obtain the views of taxpayers who used preparers, GAO surveyed a national representative sample of taxpayers.