In June 2006, the Financial Accounting Standards Board issued Interpretation No. 48, “Accounting for Uncertainty in Income Taxes: an interpretation of FASB Statement No. 109” (FIN 48). This pronouncement created a two-step process to evaluate uncertain tax positions. The first step is to determine whether the position meets a “more likely than not” (MLTN) standard for being upheld upon audit. In May of 2007, Congress, at the behest of the Internal Revenue Service, expanded the preparer penalties in IRC§6694 that are applicable to positions taken on a return. IRC§6694 adopted the MLTN standard for disclosure of a return position based upon a “reasonable basis” to believe that it is “more likely than not” that the position would be sustained at audit. This standard brought a synergy with the FIN 48 standard on tax positions. In October of 2008, IRC§6694 was again amended adopting a lesser standard of “substantial authority”. This change was made retroactive to May of 2007 and made it consistent with the disclosure standards for taxpayers. In addition the Internal Revenue Service has amended Circular 230 and the Due Diligence standards for taking a tax position. This paper will analyze the application FIN 48, IRC penalty disclosure rules and Circular 230 as they apply to professionals taking tax positions.