Summary: Internal Revenue Service (IRS) indicators show that IRS generally met or exceeded its performance goals for the 1998 tax filing season. Included in IRS indicators are measures of the timeliness of its processing of refunds, the accessibility of its telephone service, the accuracy with which it processes returns, and the accuracy of the assistance it gives over the telephone. Although millions of taxpayers used the services provided by IRS' walk-in sites during the 1998 tax filing season, the agency lacked meaningful nationwide data for assessing the performance of those sites. This report also discusses six specific areas: (1) IRS efforts to increase the use of electronic filing; (2) IRS' progress in addressing an issue discussed in GAO reports on the 1996 and 1997 filing seasons involving the use of private banks to process some tax payments; (3) IRS' implementation of the 1997 tax law change dealing with capital gains; (4) the status of IRS' efforts to reduce Earned Income Credit noncompliance; (5) the ability of taxpayers seeking assistance to reach IRS by telephone; and (6) other IRS efforts to provide information to taxpayers, such as its web site on the Internet and TeleTax. GAO also discusses IRS' test of a new processing system that has implications for future filing seasons.