The article examines the prerequisites, content and effects of changes in the corporate taxation system adopted in the United States under the Tax Cuts and Jobs Act in December 2017. The critical flaws and limitations of the US corporate taxation system that existed until 2018 are analyzed in detail. A conceptual consensus on the need to reduce the corporate tax rate and solving the problem of profit shifting existed in the US expert community for some time before the election of President D. Trump, but the balance of power in Congress made the changes impossible. The key provisions of the new corporate tax system, which primarily include a reduction in the corporate tax rate, reforming companies’ international taxation and measures to stimulate investment in the United States, are outlined. The expected consequences and first results of the reform, the impact of the adopted changes on the activities of different types of companies and on the US economy are considered. It is shown that the reform will lead to increased activity of both American and foreign companies on the US territory, as well as, possibly, a decrease in corporate tax rates in other countries. It is concluded that, despite the considerable budget burden, the tax reform will contribute to economic growth in the United States, both in the short and long run.