To amend the Internal Revenue Code of 1986 to modify the penalty on the understatement of taxpayer's liability by tax return preparers.

[AI summary unavailable — showing source text] Amends the Internal Revenue Code to modify the standards for imposing penalties on tax return preparers for understatements of tax to require: (1) substantial authority for a position with respect to an item on a tax return if such position was not disclosed with the return; and (2) a reasonable basis for a position which was disclosed with the return. Requires tax return preparers to have a reasonable belief that a position with respect to a tax shelter or a reportable transaction (a transaction having a potential for tax avoidance or evasion) will more likely than not be sustained on its merits.…