Many CPA candidates have asked about tax laws tested in the Regulation section of the CPA exam. The AICPA officially states that all tax laws in effect six months prior to an examination date are testable. However, for practical matters, current tax laws will not always be tested at the six month mark. Updating exam questions is difficult and, though the AICPA does an excellent job, it is a struggle to keep up with recent tax changes. In addition, the tax code available in the research portion of the Simulations will not always be up-to-date. If an outdated IRC is listed in the Simulation, then you must use what is available to complete the Simulation.
Moreover, specific tax rates and exemption amounts are not tested, per se. Tax rates and other variable information, as needed, are given with the questions. Candidates need to understand how to apply the given information to result in a correct answer, but they do not need to memorize specific tax laws, rates or limits.