We analyze the initial corporate response to the 2017 enactment of the “Tax Cuts and Jobs Act” (TCJA). The TCJA changed many corporate tax provisions, including a reduction of the corporate statutory tax rate from 35 percent to 21 percent effective in 2018 and sweeping changes to the taxation of income earned abroad by U.S. corporations. Based on a sample of U.S. corporate tax returns, we find that corporations accelerated deductions into 2017 and delayed income into 2018, thereby minimizing their taxes. We estimate an income and deduction shifting tax elasticity of -0.11 and 0.08, respectively. Additionally, we study detailed tax returns of 81 large corporations to understand how those changes impacted them.