Many corporations will pay a blended federal income tax this year under the new tax reform law

From IRS.com

Many U.S. corporations elect to use a fiscal year end and not a calendar year end for federal income tax reporting purposes.  Due to a provision in the recently enacted Tax Cuts and Jobs Act (TCJA), a corporation with a fiscal year that includes Jan. 1, 2018 will pay federal income tax using a blended tax rate and not the flat 21 percent tax rate under the TCJA that would generally apply to taxable years beginning after Dec. 31, 2017. 
 
Corporations determine their federal income tax for fiscal years that include Jan. 1, 2018, by first calculating their tax for the entire taxable year using the tax rates in effect prior to TCJA and then calculating their tax using the new 21 percent rate, subsequently proportioning each tax amount based on the number of days in the taxable year when the different rates were in effect.  The sum of these two amounts is the corporation’s federal income tax for the fiscal year.
 
The blended rate applies to all fiscal year corporations whose fiscal year includes Jan. 1, 2018.  Fiscal year corporations that have already filed their federal income tax returns that do not reflect the blended rate may want to consider filing an amended return. 
 
The federal sequester law remains in effect for the 2018 federal fiscal year. Corporations need to be aware of how this may affect their tax credits and refunds. Revised forms and instructions can be found on IRS.gov.
 
Updates on the implementation of the Tax Cuts and Jobs Act can be found on the Tax Reform page of IRS.gov. The Treasury media contact for this matter is Marisol Garibay, Deputy Assistant Secretary for Public Affairs, 202-622-6490.

From IRS.com