Summary: GAO discussed the Internal Revenue Code's (IRC) civil penalty provisions and their enforcement. GAO noted that: (1) IRC contains nearly 150 civil penalties; and (2) the Internal Revenue Service (IRS) assessed almost 27 million penalties totalling over $14 billion in fiscal year 1987. GAO also noted that IRS plans to study its penalty provisions structure through a methodology which: (1) draws heavily on expert opinion and advice, but does not provide for any sampling of taxpayer returns and accounts to validate experts' concerns and opinions; (2) will attempt to aggregate existing IRS statistics to enhance their usefulness in analyzing civil penalties; and (3) uses statistical data that may be misleading, inflated, and erroneous. In addition, GAO noted that IRS: (1) did not have readily available data identifying the number of computer-generated penalty assessments or the percentage of those assessments abated or erroneously paid; (2) did not assess penalties in all warranted cases; (3) made several computational and oversight errors in reviewing tax returns; and (4) inconsistently enforced penalties and inappropriately abated penalties.