The federal government has the chance to realize substantial revenue if the Internal Revenue Service (IRS) can more effectively and efficiently collect taxes already owed. Collections, however, were disappointing again this year. For the third fiscal year in a row, IRS' collection of delinquent taxes fell--from $24.2 billion in 1992 to $22.8 billion in 1993. GAO's testimony answers two questions. First, what can IRS do to collect more tax debts and at the same time treat similarly situated taxpayers the same? Second, what are some difficulties that taxpayers have had in filing returns and communicating with IRS?